Anti-notch3 antibodies

ABSTRACT

Monoclonal antibodies that bind and inhibit activation of human Notch3 are disclosed. The antibodies can be used to treat cell proliferative diseases and disorders, including certain forms of cancer, associated with activation of Notch3.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of and priority to U.S. Provisional Patent Application No. 61/866,787, filed Aug. 16, 2013, and U.S. Provisional Patent Application No. 61/739,435, filed Dec. 19, 2012, the entire disclosure of each of which is incorporated by reference herein in its entirety.

FIELD OF THE INVENTION

The field of the invention is molecular biology, immunology and oncology. More particularly, the field is antibodies that bind human Notch3.

BACKGROUND

Notch pathway signaling is involved in numerous cellular processes, including cell fate determination, differentiation, proliferation, apoptosis, migration and angiogenesis. In mammals, there are four Notch proteins (sometimes called “Notch receptors”), designated Notch1-Notch4. All four Notch proteins have a similar domain structure, which includes an extracellular domain, a negative regulatory region (NRR), a single-pass transmembrane domain, and an intracellular domain. The extracellular domain contains a series of EGF-like repeats that are involved in ligand binding. During maturation, the Notch polypeptide is cleaved by a furin-like protease. This cleavage divides the Notch protein into two subunits that are held together by noncovalent interactions of the NRR. In the absence of ligand binding, the NRR domain functions to keep the Notch protein in a protease-resistant conformation. The intracellular domain is a transcription factor called Notch intracellular domain (NICD), which is released upon proteolytic cleavage by gamma secretase, in response to binding of the Notch protein by a ligand. In mammals, the Notch ligands are Delta-like (e.g., DLL1 and DLL4) and Jagged (also referred to as Jag, e.g., Jag1 and Jag2). When the NICD is released, it travels to the nucleus, where it activates transcription of the Notch-responsive genes, HES1, HES5, NRARP, Deltex1 and c-MYC. For reviews of Notch-related biology, see, e.g., Bray, 2006, NATURE REVIEWS 7:678-689; Kopan et al., 2009, CELL 137:216-233.

While Notch proteins play crucial roles in normal development, dysregulation of the Notch proteins is associated with various types of cancer, including T-cell acute lymphatic leukemia/lymphoma (T-A11), breast cancer, colon cancer, ovarian cancer and lung cancer. See, e.g., Miele et al., 2006, CURRENT CANCER DRUG TARGETS 6:313-323. Accordingly, one therapeutic approach for the treatment of cancer is inhibition of Notch pathway signaling. Inhibition of Notch pathway signaling has been achieved using monoclonal antibodies (Wu et al., 2010, NATURE 464:1052-1057; Aste-Amezaga et al., 2010, PLOS ONE 5:1-13 e9094).

Naturally-occurring antibodies are multimeric proteins that contain four polypeptide chains (FIG. 1). Two of the polypeptide chains are called immunoglobulin heavy chains (H chains), and two of the polypeptide chains are called immunoglobulin light chains (L chains).

The immunoglobulin heavy and light chains are connected by an interchain disulfide bond. The immunoglobulin heavy chains are connected by interchain disulfide bonds. A light chain consists of one variable region (V_(L) in FIG. 1) and one constant region (C_(L) in FIG. 1). The heavy chain consists of one variable region (V_(H) in FIG. 1) and at least three constant regions (CH₁, CH₂ and CH₃ in FIG. 1). The variable regions determine the specificity of the antibody.

Each variable region contains three hypervariable regions known as complementarity determining regions (CDRs) flanked by four relatively conserved regions known as framework regions (FRs). The three CDRs, referred to as CDR₁, CDR₂, and CDR₃, contribute to the antibody binding specificity. Naturally occurring antibodies have been used as starting material for engineered antibodies, such as chimeric antibodies and humanized antibodies.

There is a need for improved antibodies that neutralize the biological activity of human Notch3 and that can be used as therapeutic agents to treat human patients.

SUMMARY OF THE INVENTION

The invention is based on the discovery of antibodies that specifically bind human Notch3. Antibodies disclosed herein contain Notch3 binding sites based on the CDRs of the anti-Notch3 antibodies described herein. The disclosed antibodies prevent or inhibit activation of human Notch3. They do so by inhibiting Notch3 from binding to Notch ligands, i.e., Jag1, Jag2, DLL1, and DLL4. The disclosed antibodies can be used to inhibit the proliferation of tumor cells in vitro and/or in vivo. When administered to a human cancer patient, the antibodies inhibit or reduce tumor growth in the human patient.

These and other aspects and advantages of the invention are illustrated by the following figures, detailed description and claims. As used herein, “including” means without limitation, and examples cited are non-limiting. As used herein, “antibody 4F11” means antibody 4F11, or humanized variants thereof.

DESCRIPTION OF THE DRAWINGS

The invention can be more completely understood with reference to the following drawings.

FIG. 1 (prior art) is a schematic representation of a typical naturally-occurring antibody.

FIG. 2 provides the amino acid sequence corresponding to the extracellular domain (ECD; amino acids 40 to 1643) of human Notch3 (SEQ ID NO:95).

FIG. 3 provides the amino acid sequence corresponding to EGF-like repeats 1-11 (amino acids 40 to 467 of the extracellular domain shown in FIG. 2) of human Notch3 (SEQ ID NO:96).

FIG. 4 is a bar chart summarizing results of an experiment to determine specificity of antibody 4F11 binding to Fc-bound recombinant human Notch3 (rhNotch3) using Octet. The results demonstrate that the binding specificity of the 4F11 antibody for rhNotch3 is much higher than for rhNotch1 or rhNotch2.

FIG. 5A is a bar chart illustrating the ability of antibody 4F11 to neutralize binding of the ligand Jag1 to human Notch3 protein. The chart shows that the antibody 4F11 and a Notch3 Specific Control, but not human immunoglobulin (hIgG), were able to block binding of recombinant human Fc-bound Jag1 (Jag1-Fc) to rhNotch3, as detected by bio-layer interferometry (BLI).

FIG. 5B is a bar chart illustrating the ability of antibody 4F11 to neutralize binding of the ligand Jag2 to human Notch3 protein. The chart shows that the antibody 4F11 and a Notch3 Specific Control, but not hIgG, were able to block binding of recombinant human Fc-bound Jag2 (Jag2-Fc) to rhNotch3, as detected by BLI.

FIG. 5C is a bar chart illustrating the ability of antibody 4F11 to neutralize binding of the ligand DLL1 to human Notch3 protein. The chart shows that the antibody 4F11 and a Notch3 Specific Control, but not hIgG, block binding of recombinant human Fc-bound DLL1 (DLL1-Fc) to rhNotch3, to a greater extent than IgG, as detected by BLI.

FIG. 5D is a bar chart illustrating the ability of antibody 4F11 to neutralize binding of the ligand DLL4 to human Notch3 protein. The chart shows that the antibody 4F11 and a Notch3 Specific Control, but not hIgG, were able to block binding of recombinant human Fc-bound DLL4 (DLL4-Fc) to rhNotch3, as detected by BLI.

FIG. 6A is a dose-response curve summarizing results from a Notch3 reporter assay showing that antibody 4F11 inhibits Notch3-dependent reporter gene expression in the presence of the Fc-bound ligand Jag2 (Jag2-Fc). The graph shows the relationship between inhibition of Jag2-Fc-stimulated reporter activity (% Inhibition) by antibody 4F11 in transduced cells, in relation to the amount of Jag2-Fc ligand. Reporter activity of cells transduced with the RBP-Jc-dependent luciferase reporter, exposed to any activating ligand, and treated with mouse IgG (mIgG) was defined as 100% activity for each ligand. Reporter activity of transduced cells not exposed to ligand but treated with mouse IgG was defined as 0% activity.

FIG. 6B is a bar chart summarizing results of Notch3 reporter assays showing that antibody 4F11, but not mouse IgG (mIgG), inhibits Notch3-dependent reporter gene expression induced by the ligands hJag1, hJag2, hDLL1 and hDLL4. Reporter activity of cells transduced with the RBP-Jκ-dependent luciferase reporter, exposed to any activating ligand, and treated with mouse IgG (mIgG) was defined as 100% activity for each ligand. Reporter activity of transduced cells not exposed to ligand but treated with mouse IgG was defined as 0% activity.

FIG. 7 is a sequence alignment showing the amino acid sequence of the complete immunoglobulin heavy chain variable region of chimeric 4F11 variable region denoted as Ch4F11 and humanized 4F11 heavy chain variable regions denoted as Sh4F11 Hy3-23, Sh4F11 Hv3-23 A28T S31H T62S, Sh4F11 Hv3-23 S31H T62S, Sh4F11 Hv3-23 A28T S31N T62S, and Sh4F11 Hv3-23 A28T T62S. The amino acid sequences for each heavy chain variable region are aligned against one another, and CDR₁, CDR₂, and CDR₃ sequences (Kabat definition) are identified in boxes. The unboxed sequences represent framework (FR) sequences.

FIG. 8 is a sequence alignment showing the isolated CDR₁, CDR₂, and CDR₃ sequences for each of the immunoglobulin heavy chain variable region sequences in FIG. 7.

FIG. 9 is a sequence alignment showing the amino acid sequence of the complete immunoglobulin light chain variable region of chimeric 4F11 denoted as Ch4F11 and humanized 4F11 light chain variable regions denoted as Hu4F11 Kv2D-29, Hu4F11 Kv2D-29 N28H, Hu4F11 Kv2D-29 N28Q, and Hu4F11 Kv2D-29 N28Y. The light chain variable region amino acid sequences are aligned against one another, and CDR₁, CDR₂, and CDR₃ sequences (Kabat definition) are identified in boxes. The unboxed sequences represent framework (FR) sequences.

FIG. 10 is a sequence alignment showing the isolated CDR₁, CDR₂, and CDR₃ sequences for each of the immunoglobulin light chain variable region sequences in FIG. 9.

FIG. 11 is a graph illustrating the ability of selected humanized 4F11 (i.e., Hu4F11-70, Hu4F11-72, Hu4F11-74, and Hu4F11-78) antibodies to inhibit ligand-induced Notch3 ICD cleavage in MDA-MB-468 cells plated on Jag2mFc. MDA-MB-468 cells exposed to either one of the 4F11 antibodies or hIgG were plated in wells coated with hJag2-mFc, incubated overnight, washed, and their lysates collected for detection of NICD by Western blot. The graph shows intensity of the cleaved NICD band in each sample as detected by Western blot. Blots were also probed with anti-β tubulin as a control, and bands were quantitated using ImageLab software. As a negative control, cells exposed to hIgG were plated in plates coated with mFc (Fc) rather than Jag2mFc.

FIG. 12A and FIG. 12B are graphs summarizing results of a Notch3 reporter assay showing that the humanized variants of 4F11 inhibit Notch3-dependent reporter gene expression induced by the ligand Jag2. CHO cells transfected with Jag2 cDNA expression vector were incubated for 24 hours with a mixture of HCC1143 reporter cells and 0.1 mg/ml, 1 mg/ml, or 10 mg/ml of 4F11 antibody variants (i.e., Hu4F11-32, Hu4F11-69, Hu4F11-70, Hu4F11-71, Hu4F11-72, Hu4F11-73, Hu4F11-74, Hu4F11-75, Hu4F11-76, Hu4F11-77, Hu4F11-78, Hu4F11-79, or Hu4F11-80), a negative control antibody (Neg Control Ab), or human immunoglobulin G (IgG), or were left untreated. 24 hours after exposing reporter cells to Jag2-expressing CHO cells, cells were processed using the Bright Glo (Promega, Madison, Wis.) reporter assay protocol and average relative light units (RLU) were detected on a GloMax Luminometer (Promega) (FIG. 12A and FIG. 12B).

FIG. 13 is a graph illustrating the ability of selected humanized 4F11 antibodies (i.e., Hu4F11-70, Hu4F11-72 and Hu4F11-78) to inhibit activation of Notch3 receptor in vivo after treatment of mice bearing HCC2429 xenograft tumors. Mice inoculated with matrigel and HCC2429 Notch3-expressing cells were allowed to develop tumors of 300-400mm³, at which point three mice (m1, m2, and m3 in FIG. 13) each were treated with 20 mg/kg of hIgG, 4F11, or humanized Notch3 antibody. Tumors were then harvested and lysates collected, and Western blotting was performed using an antibody specific for the Notch3 C-terminus in order to detect the extent of Notch intracellular domain cleavage. Western blot band intensity of the cleaved Notch intracellular domain fragment was calculated, normalizing to β-tubulin loading control.

DETAILED DESCRIPTION

The antibodies disclosed herein are based on the antigen binding sites of certain monoclonal antibodies that have been selected on the basis of binding and neutralizing the activity of human Notch3. The antibodies contain immunoglobulin variable region CDR sequences that define a binding site for human Notch3.

Because of the neutralizing activity of these antibodies, they are useful for inhibiting the growth and/or proliferation of certain cancer cells and tumors. The antibodies can be engineered (e.g., humanized) to minimize or eliminate an immune response when administered as a therapeutic antibody to a human patient. Various features and aspects of the invention are discussed in more detail below.

As used herein, unless otherwise indicated, the term “antibody” means an intact antibody (e.g., an intact monoclonal antibody) or antigen-binding fragment of an antibody, including an intact antibody or antigen-binding fragment that has been modified, engineered or chemically conjugated. Examples of antibodies that have been modified or engineered are chimeric antibodies, humanized antibodies, and multispecific antibodies (e.g., bispecific antibodies). Examples of antigen-binding fragments include Fab, Fab′, F(ab′)₂, Fv, single chain antibodies (e.g., scFv), minibodies, and diabodies. An antibody conjugated to a toxin moiety is an example of a chemically conjugated antibody.

I. Antibodies that Bind Human Notch3

As disclosed herein, the antibodies may comprise: (a) an immunoglobulin heavy chain variable region comprising the structure CDR_(H1)-CDR_(H2)-CDR_(H3) and (b) an immunoglobulin light chain variable region comprising the structure CDR_(L1)-CDR_(L2)-CDR_(L3), wherein the heavy chain variable region and the light chain variable region together define a single binding site for binding human Notch3.

In some embodiments, the antibody comprises: (a) an immunoglobulin heavy chain variable region comprising the structure CDR_(H1)-CDR_(H2)-CDR_(H3) and (b) an immunoglobulin light chain variable region, wherein the heavy chain variable region and the light chain variable region together define a single binding site for binding human Notch3. A CDR_(H1) comprises an amino acid sequence selected from the group consisting of SEQ ID NO:5, SEQ ID NO:11, SEQ ID NO:14, SEQ ID NO:51, SEQ ID NO:52, SEQ ID NO:54, SEQ ID NO:55, SEQ ID NO:56, SEQ ID NO:57, SEQ ID NO:58, SEQ ID NO:59, SEQ ID NO:60 and SEQ ID NO:61; a CDR_(H2) comprises an amino acid sequence selected from the group consisting of SEQ ID NO:6, SEQ ID NO:12, SEQ ID NO:15 and SEQ ID NO:53; and a CDR_(H3) comprises an amino acid sequence selected from the group consisting of SEQ ID NO:7 and SEQ ID NO:16. (The immunoglobulin heavy chain variable regions including the referenced CDR sequences can be found in Table 10 and FIGS. 7-8.)

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 5 and SEQ ID NO: 11, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO: 6, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO: 7.

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 51 and SEQ ID NO: 54, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO: 53, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO: 7.

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 51 and SEQ ID NO: 55, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO: 53, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO: 7.

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 52 and SEQ ID NO: 56, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO: 53, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO: 7.

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 5 and SEQ ID NO: 57, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO: 53, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO: 7.

Preferably, the CDR_(H1), CDR_(H2), and CDR_(H3) sequences are interposed between human or humanized immunoglobulin FR sequences.

In other embodiments, the antibody comprises (a) an immunoglobulin light chain variable region comprising the structure CDR_(L1)-CDR_(L2)-CDR_(L3), and (b) an immunoglobulin heavy chain variable region, wherein the IgG light chain variable region and the IgG heavy chain variable region together define a single binding site for binding human Notch3. A CDR_(L1) comprises an amino acid sequence selected from the group consisting of SEQ ID NO:8, SEQ ID NO:20, SEQ ID NO:62, SEQ ID NO:63, SEQ ID NO:64, SEQ ID NO:65, SEQ ID NO:66 and SEQ ID NO:67; a CDR_(L2) comprises an amino acid sequence selected from the group consisting of SEQ ID NO:9 or the amino acid sequence of KVS; and a CDR_(L3) comprises an amino acid sequence of SEQ ID NO:10. (The immunoglobulin light chain variable regions including the referenced CDR sequences can be found in Table 11 and FIGS. 9-10.)

In some embodiments, the antibody comprises an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO: 8, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO: 9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO: 10.

In some embodiments, the antibody comprises an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO: 62, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO: 9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO: 10.

In some embodiments, the antibody comprises an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO: 63, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO: 9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO: 10.

In some embodiments, the antibody comprises an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO: 64, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO: 9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO: 10.

Preferably, the CDR_(L1), CDR_(L2), and CDR_(L3) sequences are interposed between human or humanized immunoglobulin FR sequences.

In some embodiments, the antibody comprises: (a) an immunoglobulin heavy chain variable region comprising the structure CDR_(H1)-CDR_(H2)-CDR_(H3) and (b) an immunoglobulin light chain variable region comprising the structure CDR_(L1)-CDR_(L2)-CDR_(L3), wherein the heavy chain variable region and the light chain variable region together define a single binding site for binding human Notch3. The CDR_(H1) comprises an amino acid sequence selected from the group consisting of SEQ ID NO:5, SEQ ID NO:11, SEQ ID NO:14, SEQ ID NO:51, SEQ ID NO:52, SEQ ID NO:54, SEQ ID NO:55, SEQ ID NO:56, SEQ ID NO:57, SEQ ID NO:58, SEQ ID NO:59, SEQ ID NO:60 and SEQ ID NO:61; the CDR_(H2) comprises an amino acid sequence selected from the group consisting of SEQ ID NO:6, SEQ ID NO:12, SEQ ID NO:15 and SEQ ID NO:53; and the CDR_(H3) comprises an amino acid sequence selected from the group consisting of SEQ ID NO:7 and SEQ ID NO:16. The CDR_(L1) comprises an amino acid sequence selected from the group consisting of SEQ ID NO:8, SEQ ID NO:20, SEQ ID NO:62, SEQ ID NO:63, SEQ ID NO:64, SEQ ID NO:65, SEQ ID NO:66 and SEQ ID NO:67; the CDR_(L2) comprises an amino acid sequence selected from the group consisting of SEQ ID NO:9 or the amino acid sequence of KVS; and the CDR_(L3) comprises an amino acid sequence of SEQ ID NO:10.

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO:5 and SEQ ID NO:11, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO:6, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO:7; and an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO:8, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO:9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO:10.

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 5 and SEQ ID NO:11; a CDR_(H2) comprising the amino acid sequence of SEQ ID NO: 6; and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO: 7; and an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO: 62; a CDR_(L2) comprising the amino acid sequence of SEQ ID NO: 9; and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO: 10.

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 5 and SEQ ID NO:11; a CDR_(H2) comprising the amino acid sequence of SEQ ID NO: 6; and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO: 7; and an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO: 63; a CDR_(L2) comprising the amino acid sequence of SEQ ID NO: 9; and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO: 10.

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 5 and SEQ ID NO:11; a CDR_(H2) comprising the amino acid sequence of SEQ ID NO: 6; and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO: 7; and an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO: 64; a CDR_(L2) comprising the amino acid sequence of SEQ ID NO: 9; and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO: 10.

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO:51 and SEQ ID NO: 54, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO:53, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO:7; and an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO:8, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO:9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO:10.

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO:51 and SEQ ID NO: 54, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO:53, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO:7; and an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO:62, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO:9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO:10.

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO:51 and SEQ ID NO: 54, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO:53, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO:7; and an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO:63, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO:9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO:10.

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO:51 and SEQ ID NO: 54, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO:53, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO:7; and an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO:64, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO:9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO:10.

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO:51 and SEQ ID NO: 55, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO:53, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO:7; and an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO:8, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO:9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO:10.

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO:51 and SEQ ID NO: 55, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO:53, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO:7; and an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO:62, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO:9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO:10.

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO:51 and SEQ ID NO: 55, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO:53, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO:7; and an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO:63, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO:9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO:10.

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO:51 and SEQ ID NO: 55, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO:53, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO:7; and an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO:64, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO:9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO:10.

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO:52 and SEQ ID NO: 56, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO:53, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO:7; and an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO:8, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO:9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO:10.

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO:52 and SEQ ID NO: 56, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO:53, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO:7; and an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO:62, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO:9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO:10.

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO:52 and SEQ ID NO: 56, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO:53, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO:7; and an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO:63, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO:9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO:10.

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO:52 and SEQ ID NO: 56, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO:53, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO:7; and an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO:64, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO:9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO:10.

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO:5 and SEQ ID NO: 57, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO:53, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO:7; and an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO:8, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO:9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO:10.

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO:5 and SEQ ID NO: 57, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO:53, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO:7; and an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO:62, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO:9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO:10.

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO:5 and SEQ ID NO: 57, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO:53, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO:7; and an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO:63, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO:9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO:10.

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO:5 and SEQ ID NO: 57, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO:53, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO:7; and an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO:64, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO:9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO:10.

The antibodies disclosed herein comprise an immunoglobulin heavy chain variable region and an immunoglobulin light chain variable region. In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region selected from the group consisting of SEQ ID NO:2 (4F11, Ch4F11 Chimeric); SEQ ID NO:34 (Sh4F11 Hv3-23); SEQ ID NO:36 (Sh4F11 Hv3-23 A28T S31H T62S); SEQ ID NO:38 (Sh4F11 Hv3-23 S31H T62S); SEQ ID NO:40 (Sh4F11 Hv3-23 A28T S31N T62S); and SEQ ID NO:42 (Sh4F11 Hv3-23 A28T T62S); and an immunoglobulin light chain variable region. As a convenience for the reader, certain SEQ ID NOs. are followed by a parenthetical including the antibody designation that was the origin of the sequence. For example, “SEQ ID NO:2 (4F11, Ch4F11 Chimeric)” means that SEQ ID NO:2 comes from murine antibody 4F11. SEQ ID NO:2 is also found in the chimeric 4F11 sequence.

In other embodiments, the antibody comprises an immunoglobulin light chain variable region selected from the group consisting of SEQ ID NO:4 (4F11, Ch4F11 Chimeric); SEQ ID NO:44 (Hu4F11 Kv2D-29); SEQ ID NO:46 (Hu4F11 Kv2D-29 N28H); SEQ ID NO:48 (Hu4F11 Kv2D-29 N28Q); and SEQ ID NO:50 (Hu4F11 Kv2D-29 N28Y); and an immunoglobulin heavy chain variable region.

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region selected from the group consisting of SEQ ID NO:2 (4F11, Ch4F11 Chimeric); SEQ ID NO:34 (Sh4F11 Hv3-23); SEQ ID NO:36 (Sh4F11 Hv3-23 A28T S31H T62S); SEQ ID NO:38 (Sh4F11 Hv3-23 S31H T62S); SEQ ID NO:40 (Sh4F11 Hv3-23 A28T S31N T62S); and SEQ ID NO:42 (Sh4F11 Hv3-23 A28T T62S), and an immunoglobulin light chain variable region selected from the group consisting of SEQ ID NO:4 (4F11, Ch4F11 Chimeric); SEQ ID NO:44 (Hu4F11 Kv2D-29); SEQ ID NO:46 (Hu4F11 Kv2D-29 N28H); SEQ ID NO:48 (Hu4F11 Kv2D-29 N28Q); and SEQ ID NO:50 (Hu4F11 Kv2D-29 N28Y).

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising the amino acid sequence of SEQ ID NO:2 (4F11, Ch4F11 Chimeric), and an immunoglobulin light chain variable region comprising the amino acid sequence of SEQ ID NO:4 (4F11, Ch4F11 Chimeric).

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising the amino acid sequence of SEQ ID NO:2 (4F11, Ch4F11 Chimeric), and an immunoglobulin light chain variable region comprising the amino acid sequence of SEQ ID NO:44 (Hu4F11 Kv2D-29).

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising the amino acid sequence of SEQ ID NO:34 (Sh4F11 Hv3-23), and an immunoglobulin light chain variable region comprising the amino acid sequence of SEQ ID NO:4 (4F11, Ch4F11 Chimeric).

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising the amino acid sequence of SEQ ID NO:34 (Sh4F11 Hv3-23), and an immunoglobulin light chain variable region comprising the amino acid sequence of SEQ ID NO:44 (Hu4F11 Kv2D-29).

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising the amino acid sequence of SEQ ID NO:36 (Sh4F11 Hv3-23 A28T S31H T62S), and an immunoglobulin light chain variable region comprising the amino acid sequence of SEQ ID NO:46 (Hu4F11 Kv2D-29 N28H).

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising the amino acid sequence of SEQ ID NO:38 (Sh4F11 Hv3-23 S31H T62S), and an immunoglobulin light chain variable region comprising the amino acid sequence of SEQ ID NO:46 (Hu4F11 Kv2D-29 N28H).

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising the amino acid sequence of SEQ ID NO:40 (Sh4F11 Hv3-23 A28T S31N T62S), and an immunoglobulin light chain variable region comprising the amino acid sequence of SEQ ID NO:46 (Hu4F11 Kv2D-29 N28H).

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising the amino acid sequence of SEQ ID NO:42 (Sh4F11 Hv3-23 A28T T62S), and an immunoglobulin light chain variable region comprising the amino acid sequence of SEQ ID NO:46 (Hu4F11 Kv2D-29 N28H).

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising the amino acid sequence of SEQ ID NO:36 (Sh4F11 Hv3-23 A28T S31H T62S), and an immunoglobulin light chain variable region comprising the amino acid sequence of SEQ ID NO:48 (Hu4F11 Kv2D-29 N28Q).

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising the amino acid sequence of SEQ ID NO:38 (Sh4F11 Hv3-23 S31H T62S), and an immunoglobulin light chain variable region comprising the amino acid sequence of SEQ ID NO:48 (Hu4F11 Kv2D-29 N28Q).

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising the amino acid sequence of SEQ ID NO:40 (Sh4F11 Hv3-23 A28T S31N T62S), and an immunoglobulin light chain variable region comprising the amino acid sequence of SEQ ID NO:48 (Hu4F11 Kv2D-29 N28Q).

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising the amino acid sequence of SEQ ID NO:42 (Sh4F11 Hv3-23 A28T T62S), and an immunoglobulin light chain variable region comprising the amino acid sequence of SEQ ID NO:48 (Hu4F11 Kv2D-29 N28Q).

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising the amino acid sequence of SEQ ID NO:36 (Sh4F11 Hv3-23 A28T S31H T62S), and an immunoglobulin light chain variable region comprising the amino acid sequence of SEQ ID NO:50 (Hu4F11 Kv2D-29 N28Y).

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising the amino acid sequence of SEQ ID NO:38 (Sh4F11 Hv3-23 S31H T62S), and an immunoglobulin light chain variable region comprising the amino acid sequence of SEQ ID NO:50 (Hu4F11 Kv2D-29 N28Y).

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising the amino acid sequence of SEQ ID NO:40 (Sh4F11 Hv3-23 A28T S31N T62S), and an immunoglobulin light chain variable region comprising the amino acid sequence of SEQ ID NO:50 (Hu4F11 Kv2D-29 N28Y).

In some embodiments, the antibody comprises an immunoglobulin heavy chain variable region comprising the amino acid sequence of SEQ ID NO:42 (Sh4F11 Hv3-23 A28T T62S), and an immunoglobulin light chain variable region comprising the amino acid sequence of SEQ ID NO:50 (Hu4F11 Kv2D-29 N28Y).

In certain embodiments, the antibodies disclosed herein comprise an immunoglobulin heavy chain and an immunoglobulin light chain. In some embodiments, the antibody comprises an immunoglobulin heavy chain selected from the group consisting of SEQ ID NO: 27 (4F11); SEQ ID NO:74 (Ch4F11 Chimeric); SEQ ID NO:76 (Sh4F11 Hv3-23); SEQ ID NO:78 (Sh4F11 Hv3-23 A28T S31H T62S); SEQ ID NO:80 (Sh4F11 Hv3-23 S31H T62S); SEQ ID NO:82 (Sh4F11 Hv3-23 A28T S31N T62S); and SEQ ID NO:84 (Sh4F11 Hv3-23 A28T T62S); and an immunoglobulin light chain.

In other embodiments, the antibody comprises an immunoglobulin light chain selected from the group consisting of SEQ ID NO:29 (4F11); SEQ ID NO:86 (Ch4F11 Chimeric); SEQ ID NO:88 (Hu4F11 Kv2D-29 Kappa); SEQ ID NO:90 (Hu4F11 Kv2D-29 N28H Kappa); SEQ ID NO:92 (Hu4F11 Kv2D-29 N28Q Kappa); and SEQ ID NO:94 (Hu4F11 Kv2D-29 N28Y Kappa); and an immunoglobulin heavy chain.

In some embodiments, the antibody comprises an immunoglobulin heavy chain selected from the group consisting of SEQ ID NO: 27 (4F11); SEQ ID NO:74 (Ch4F11 Chimeric); SEQ ID NO:76 (Sh4F11 Hv3-23); SEQ ID NO:78 (Sh4F11 Hv3-23 A28T S31H T62S); SEQ ID NO:80 (Sh4F11 Hv3-23 S31H T62S); SEQ ID NO:82 (Sh4F11 Hv3-23 A28T S31N T62S); and SEQ ID NO:84 (Sh4F11 Hv3-23 A28T T62S); and an immunoglobulin light chain selected from the group consisting of SEQ ID NO:29 (4F11); SEQ ID NO:86 (Ch4F11 Chimeric); SEQ ID NO:88 (Hu4F11 Kv2D-29 Kappa); SEQ ID NO:90 (Hu4F11 Kv2D-29 N28H Kappa); SEQ ID NO:92 (Hu4F11 Kv2D-29 N28Q Kappa); and SEQ ID NO:94 (Hu4F11 Kv2D-29 N28Y Kappa).

In some embodiments, the antibody comprises an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 27 (4F11), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 29 (4F11).

In some embodiments, the antibody comprises an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 74 (Ch4F11), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 86 (Ch4F11).

In some embodiments, the antibody comprises an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 74 (Ch4F11), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 88 (Hu4F11 Kv2D-29).

In some embodiments, the antibody comprises an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 76 (Sh4F11 Hv3-23), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 86 (Ch4F11).

In some embodiments, the antibody comprises an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 76 (Sh4F11 Hv3-23), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 88 (Hu4F11 Kv2D-29).

In some embodiments, the antibody comprises an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 78 (Sh4F11 Hv3-23 A28T S31H T62S), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 90 (Hu4F11 Kv2D-29 N28H Kappa).

In some embodiments, the antibody comprises an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 80 (Sh4F11 Hv3-23 S31H T62S), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 90 (Hu4F11 Kv2D-29 N28H Kappa).

In some embodiments, the antibody comprises an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 82 (Sh4F11 Hv3-23 A28T S31N T62S), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 90 (Hu4F11 Kv2D-29 N28H Kappa).

In some embodiments, the antibody comprises an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 84 (Sh4F11 Hv3-23 A28T T62S), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 90 (Hu4F11 Kv2D-29 N28H Kappa).

In some embodiments, the antibody comprises an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 78 (Sh4F11 Hv3-23 A28T S31H T62S), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 92 (Hu4F11 Kv2D-29 N28Q Kappa).

In some embodiments, the antibody comprises an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 80 (Sh4F11 Hv3-23 S31H T62S), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 92 (Hu4F11 Kv2D-29 N28Q Kappa).

In some embodiments, the antibody comprises an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 82 (Sh4F11 Hv3-23 A28T S31N T62S), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 92 (Hu4F11 Kv2D-29 N28Q Kappa).

In some embodiments, the antibody comprises an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 84 (Sh4F11 Hv3-23 A28T T62S), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 92 (Hu4F11 Kv2D-29 N28Q Kappa).

In some embodiments, the antibody comprises an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 78 (Sh4F11 Hv3-23 A28T S31H T62S), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 94 (Hu4F11 Kv2D-29 N28Y Kappa).

In some embodiments, the antibody comprises an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 80 (Sh4F11 Hv3-23 S31H T62S), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 94 (Hu4F11 Kv2D-29 N28Y Kappa).

In some embodiments, the antibody comprises an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 82 (Sh4F11 Hv3-23 A28T S31N T62S), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 94 (Hu4F11 Kv2D-29 N28Y Kappa).

In some embodiments, the antibody comprises an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 84 (Sh4F11 Hv3-23 A28T T62S), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 94 (Hu4F11 Kv2D-29 N28Y Kappa).

In other embodiments, an isolated antibody that binds human Notch3 comprises an immunoglobulin heavy chain variable region comprising an amino acid sequence that is at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, or 99% identical to the entire variable region or the FR sequence of SEQ ID NO:2 (4F11, Ch4F11 Chimeric); SEQ ID NO:34 (Sh4F11 Hv3-23); SEQ ID NO:36 (Sh4F11 Hv3-23 A28T S31H T62S); SEQ ID NO:38 (Sh4F11 Hv3-23 S31H T62S); SEQ ID NO:40 (Sh4F11 Hv3-23 A28T S31N T62S); or SEQ ID NO:42 (Sh4F11 Hv3-23 A28T T62S).

In other embodiments, an isolated antibody that binds human Notch3 comprises an immunoglobulin light chain variable region comprising an amino acid sequence that is at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, or 99% identical to the entire variable region or the FR sequence of SEQ ID NO:4 (4F11, Ch4F11 Chimeric); SEQ ID NO:44 (Hu4F11 Kv2D-29); SEQ ID NO:46 (Hu4F11 Kv2D-29 N28H); SEQ ID NO:48 (Hu4F11 Kv2D-29 N28Q); or SEQ ID NO:50 (Hu4F11 Kv2D-29 N28Y).

Sequence identity may be determined in various ways that are within the skill of a person skilled in the art, e.g., using publicly available computer software such as BLAST, BLAST-2, ALIGN or Megalign (DNASTAR) software. BLAST (Basic Local Alignment

Search Tool) analysis using the algorithm employed by the programs blastp, blastn, blastx, tblastn and tblastx (Karlin et al., (1990) PROC. NATL. ACAD. SCI. USA 87:2264-2268; Altschul, (1993) J. MOL. EVOL. 36:290-300; Altschul et al., (1997) NUCLEIC ACIDS RES. 25:3389-3402, herein incorporated by reference) are tailored for sequence similarity searching. For a discussion of basic issues in searching sequence databases see Altschul et al., (1994) NATURE GENETICS 6:119-129, herein fully incorporated by reference. Those skilled in the art can determine appropriate parameters for measuring alignment, including any algorithms needed to achieve maximal alignment over the full length of the sequences being compared. The search parameters for histogram, descriptions, alignments, expect (i.e., the statistical significance threshold for reporting matches against database sequences), cutoff, matrix and filter are at the default settings. The default scoring matrix used by blastp, blastx, tblastn, and tblastx is the BLOSUM62 matrix (Henikoff et al., (1992) PROC. NATL. ACAD. SCI. USA 89:10915-10919, fully incorporated by reference herein). Four blastn parameters may be adjusted as follows: Q=10 (gap creation penalty); R=10 (gap extension penalty); wink=1 (generates word hits at every wink.sup.th position along the query); and gapw=16 (sets the window width within which gapped alignments are generated). The equivalent Blastp parameter settings may be Q=9; R=2; wink=1; and gapw=32. Searches may also be conducted using the NCBI (National Center for Biotechnology Information) BLAST Advanced Option parameter (e.g.: −G, Cost to open gap [Integer]: default=5 for nucleotides/11 for proteins; −E, Cost to extend gap [Integer]: default=2 for nucleotides/1 for proteins; −q, Penalty for nucleotide mismatch [Integer]: default=−3; −r, reward for nucleotide match [Integer]: default=1; −e, expect value [Real]: default=10; −W, wordsize [Integer]: default=11 for nucleotides/28 for megablast/3 for proteins; −y, Dropoff (X) for blast extensions in bits: default=20 for blastn/7 for others; −X, X dropoff value for gapped alignment (in bits): default=15 for all programs, not applicable to blastn; and −Z, final X dropoff value for gapped alignment (in bits): 50 for blastn, 25 for others). ClustalW for pairwise protein alignments may also be used (default parameters may include, e.g., Blosum62 matrix and Gap Opening Penalty=10 and Gap Extension Penalty=0.1). A Bestfit comparison between sequences, available in the GCG package version 10.0, uses DNA parameters GAP=50 (gap creation penalty) and LEN=3 (gap extension penalty) and the equivalent settings in protein comparisons are GAP=8 and LEN=2.

In each of the foregoing embodiments, it is contemplated herein that immunoglobulin heavy chain variable region sequences and/or light chain variable region sequences that together bind human Notch3 may contain amino acid alterations (e.g., at least 1, 2, 3, 4, 5, or 10 amino acid substitutions, deletions, or additions) in the framework regions of the heavy and/or light chain variable regions.

In certain embodiments, an isolated antibody binds human Notch3 with a K_(D) of about 35 nM, 25 nM, 15 nM 10 nM, 5 nM, 1 nM, 900 pM, 850 pM, 800 pM, 750 pM, 700 pM, 650 pM, 600 pM, 500 pM, 400 pM, 300 pM, 250 pM, 200 pM or less. Unless otherwise specified, K_(D) values are determined by surface plasmon resonance methods under the conditions described in Examples 3 and 9.

In some embodiments, monoclonal antibodies bind to the same epitope on human Notch3 as antibody 4F11. In some embodiments, monoclonal antibodies compete for binding to human Notch3 with antibody 4F11. For example, monoclonal antibodies may compete for binding to the extracellular domain (ECD) of Notch3 with antibody 4F11 (amino acid sequence corresponding to the human Notch3 ECD is shown in FIG. 2). In another example, monoclonal antibodies may compete for binding to EGF-like repeats 1-11 of human Notch3 with antibody 4F11 (amino acid sequence corresponding to EGF-like repeats 1-11 of human Notch3 is shown in FIG. 3).

Competition assays for determining whether an antibody binds to the same epitope as, or competes for binding with, antibody 4F11 are known in the art. Exemplary competition assays include immunoassays (e.g., ELISA assays, RIA assays), BIAcore analysis, biolayer interferometry and flow cytometry.

Typically, a competition assay involves the use of an antigen (e.g., a human Notch3 protein or fragment thereof) bound to a solid surface or expressed on a cell surface, a test anti-Notch3-binding antibody and a reference antibody (i.e., antibody 4F11). The reference antibody is labeled and the test antibody is unlabeled. Competitive inhibition is measured by determining the amount of labeled reference antibody bound to the solid surface or cells in the presence of the test antibody. Usually the test antibody is present in excess (e.g., 1×, 5×, 10×, 20× or 100×). Antibodies identified by competition assay (i.e., competing antibodies) include antibodies binding to the same epitope, or similar (e.g., overlapping) epitopes, as the reference antibody, and antibodies binding to an adjacent epitope sufficiently proximal to the epitope bound by the reference antibody for steric hindrance to occur.

In an exemplary competition assay, a reference anti-Notch3 antibody (i.e., antibody 4F11) is biotinylated using commercially available reagents. The biotinylated reference antibody is mixed with serial dilutions of the test antibody or unlabeled reference antibody (self-competition control) resulting in a mixture of various molar ratios (e.g., 1×, 5×, 10×, 20× or 100×) of test antibody (or unlabeled reference antibody) to labeled reference antibody. The antibody mixture is added to a human Notch3 (e.g., extracellular domain of human Notch3) polypeptide coated-ELISA plate. The plate is then washed and horseradish peroxidase (HRP)-strepavidin is added to the plate as the detection reagent. The amount of labeled reference antibody bound to the target antigen is detected following addition of a chromogenic substrate (e.g., TMB (3,3′,5,5′-tetramethylbenzidine) or ABTS (2,2″-azino-di-(3-ethylbenzthiazoline-6-sulfonate)), which are known in the art. Optical density readings (OD units) are measured using a SpectraMax® M2 spectrometer (Molecular Devices). OD units corresponding to zero percent inhibition are determined from wells without any competing antibody. OD units corresponding to 100% inhibition, i.e., the assay background are determined from wells without any labeled reference antibody or test antibody. Percent inhibition of labeled reference antibody to Notch3 by the test antibody (or the unlabeled reference antibody) at each concentration is calculated as follows: % inhibition=(1−(OD units−100% inhibition)/(0% inhibition−100% inhibition))*100. Persons skilled in the art will appreciate that the competition assay can be performed using various detection systems known in the art.

A competition assay may be conducted in both directions to ensure that the presence of the label does not interfere or otherwise inhibit binding. For example, in the first direction the reference antibody is labeled and the test antibody is unlabeled, and in the second direction, the test antibody is labeled and the reference antibody is unlabeled.

A test antibody competes with the reference antibody for specific binding to the antigen if an excess of one antibody (e.g., 1×, 5×, 10×, 20× or 100×) inhibits binding of the other antibody, e.g., by at least 50%, 75%, 90%, 95% or 99% as measured in a competitive binding assay.

Two antibodies may be determined to bind to the same epitope if essentially all amino acid mutations in the antigen that reduce or eliminate binding of one antibody reduce or eliminate binding of the other. Two antibodies may be determined to bind to overlapping epitopes if only a subset of the amino acid mutations that reduce or eliminate binding of antibody reduce or eliminate binding of the other.

II. Antibody Production

Methods for producing antibodies of the invention are known in the art. For example, DNA molecules encoding light chain variable regions and/or heavy chain variable regions can be chemically synthesized using the sequence information provided herein. Synthetic DNA molecules can be ligated to other appropriate nucleotide sequences, including, e.g., constant region coding sequences, and expression control sequences, to produce conventional gene expression constructs encoding the desired antibody. Production of defined gene constructs is within routine skill in the art. Alternatively, the sequences provided herein can be cloned out of hybridomas by conventional hybridization techniques or polymerase chain reaction (PCR) techniques, using synthetic nucleic acid probes whose sequences are based on sequence information provided herein, or prior art sequence information regarding genes encoding the heavy and light chains of murine antibodies in hybridoma cells.

Nucleic acids encoding desired antibodies can be incorporated (ligated) into expression vectors, which can be introduced into host cells through conventional transfection or transformation techniques. Exemplary host cells are E. coli cells, Chinese hamster ovary (CHO) cells, HeLa cells, baby hamster kidney (BHK) cells, monkey kidney cells (COS), human hepatocellular carcinoma cells (e.g., Hep G2), and myeloma cells that do not otherwise produce IgG protein. Transformed host cells can be grown under conditions that permit the host cells to express the genes that encode the immunoglobulin light and/or heavy chain variable regions.

Specific expression and purification conditions will vary depending upon the expression system employed. For example, if a gene is to be expressed in E. coli, it is first cloned into an expression vector by positioning the engineered gene downstream from a suitable bacterial promoter, e.g., Trp or Tac, and a prokaryotic signal sequence. The expressed secreted protein accumulates in refractile or inclusion bodies, and can be harvested after disruption of the cells by French press or sonication. The refractile bodies then are solubilized, and the proteins refolded and cleaved by methods known in the art.

If the engineered gene is to be expressed in eukaryotic host cells, e.g., CHO cells, it is first inserted into an expression vector containing a suitable eukaryotic promoter, a secretion signal, a poly A sequence, and a stop codon, and, optionally, may contain enhancers, and various introns. This expression vector optionally contains sequences encoding all or part of a constant region, enabling an entire, or a part of, a heavy or light chain to be expressed. The gene construct can be introduced into eukaryotic host cells using conventional techniques. The host cells express V_(L) or V_(H) fragments, V_(L)-V_(H) heterodimers, V_(H)-V_(L) or V_(L)-V_(H) single chain polypeptides, complete heavy or light immunoglobulin chains, or portions thereof, each of which may be attached to a moiety having another function (e.g., cytotoxicity). In some embodiments, a host cell is transfected with a single vector expressing a polypeptide expressing an entire, or part of, a heavy chain (e.g., a heavy chain variable region) or a light chain (e.g., a light chain variable region). In other embodiments, a host cell is transfected with a single vector encoding (a) a polypeptide comprising a heavy chain variable region and a polypeptide comprising a light chain variable region, or (b) an entire immunoglobulin heavy chain and an entire immunoglobulin light chain. In still other embodiments, a host cell is co-transfected with more than one expression vector (e.g., one expression vector encoding a polypeptide comprising an entire, or part of, a heavy chain or heavy chain variable region, and another expression vector encoding a polypeptide comprising an entire, or part of, a light chain or light chain variable region).

A polypeptide comprising an immunoglobulin heavy chain variable region or light chain variable region can be produced by growing (culturing) a host cell transfected with an expression vector encoding such variable region, under conditions that permit expression of the polypeptide. Following expression, the polypeptide can be harvested and purified or isolated using techniques known in the art, e.g., affinity tags such as glutathione-S-transferase (GST) and histidine tags.

A monoclonal antibody that binds human Notch3, or an antigen-binding fragment of the antibody, can be produced by growing (culturing) a host cell transfected with: (a) an expression vector that encodes a complete or partial immunoglobulin heavy chain, and a separate expression vector that encodes a complete or partial immunoglobulin light chain; or (b) a single expression vector that encodes both chains (e.g., complete or partial heavy and light chains), under conditions that permit expression of both chains. The intact antibody (or antigen-binding fragment of the antibody) can be harvested and purified or isolated using techniques known in the art, e.g., Protein A, Protein G, affinity tags such as glutathione-S-transferase (GST) and histidine tags. It is within ordinary skill in the art to express the heavy chain and the light chain from a single expression vector or from two separate expression vectors.

III. Antibody Modifications

Methods for reducing or eliminating the antigenicity of antibodies and antibody fragments are known in the art. When administered to a human, the disclosed antibodies preferably are “humanized” to reduce or eliminate antigenicity in humans. Preferably, the humanized antibodies have the same, or substantially the same, affinity for the antigen as the non-humanized mouse antibody from which it was derived.

In one humanization approach, chimeric proteins are created in which mouse immunoglobulin constant regions are replaced with human immunoglobulin constant regions. See, e.g., Morrison et al. ,1984, PROC. NAT. ACAD. SCI. 81:6851-6855, Neuberger et al., 1984, NATURE 312:604-608; U.S. Pat. No. 6,893,625 (Robinson); U.S. Pat. No. 5,500,362 (Robinson); and U.S. Pat. No. 4,816,567 (Cabilly).

In an approach known as CDR grafting, the CDRs of the light and heavy chain variable regions are grafted into frameworks from another species. For example, murine CDRs can be grafted into human FRs. In some embodiments of the invention, the CDRs of the light and heavy chain variable regions of an anti-Notch3 antibody are grafted into human FRs or consensus human FRs. To create consensus human FRs, FRs from several human heavy chain or light chain amino acid sequences are aligned to identify a consensus amino acid sequence. CDR grafting is described in U.S. Pat. No. 7,022,500 (Queen); U.S. Pat. No. 6,982,321 (Winter); U.S. Pat. No. 6,180,370 (Queen); U.S. Pat. No. 6,054,297 (Carter); U.S. Pat. No. 5,693,762 (Queen); U.S. Pat. No. 5,859,205 (Adair); U.S. Pat. No. 5,693,761 (Queen); U.S. Pat. No. 5,565,332 (Hoogenboom); U.S. Pat. No. 5,585,089 (Queen); U.S. Pat. No. 5,530,101 (Queen); Jones et al. (1986) NATURE 321: 522-525; Riechmann et al. (1988) NATURE 332: 323-327; Verhoeyen et al. (1988) SCIENCE 239: 1534-1536; and Winter (1998) FEBS LETT 430: 92-94.

In an approach called “SUPERHUMANIZATION™,” human CDR sequences are chosen from human germline genes, based on the structural similarity of the human CDRs to those of the mouse antibody to be humanized. See, e.g., U.S. Pat. No. 6,881,557 (Foote); and Tan et al., 2002, J. IMMUNOL 169:1119-1125.

Other methods to reduce immunogenicity include “reshaping,” “hyperchimerization,” and “veneering/resurfacing.” See, e.g., Vaswami et al., 1998, ANNALS OF ALLERGY, ASTHMA, & IMMUNOL. 81:105; Roguska et al., 1996, PROT. ENGINEER 9:895-904; and U.S. Pat. No. 6,072,035 (Hardman). In the veneering/resurfacing approach, the surface accessible amino acid residues in the murine antibody are replaced by amino acid residues more frequently found at the same positions in a human antibody. This type of antibody resurfacing is described, e.g., in U.S. Pat. No. 5,639,641 (Pedersen).

Another approach for converting a mouse antibody into a form suitable for medical use in humans is known as ACTIVMAB™ technology (Vaccinex, Inc., Rochester, N.Y.), which involves a vaccinia virus-based vector to express antibodies in mammalian cells. High levels of combinatorial diversity of IgG heavy and light chains are said to be produced. See, e.g., U.S. Pat. No. 6,706,477 (Zauderer); U.S. Pat. No. 6,800,442 (Zauderer); and U.S. Pat. No. 6,872,518 (Zauderer).

Another approach for converting a mouse antibody into a form suitable for use in humans is technology practiced commercially by KaloBios Pharmaceuticals, Inc. (Palo Alto, Calif.). This technology involves the use of a proprietary human “acceptor” library to produce an “epitope focused” library for antibody selection.

Another approach for modifying a mouse antibody into a form suitable for medical use in humans is HUMAN ENGINEERING™ technology, which is practiced commercially by XOMA (US) LLC. See, e.g., PCT Publication No. WO 93/11794 and U.S. Pat. No.

5,766,886 (Studnicka); U.S. Pat. No. 5,770,196 (Studnicka); U.S. Pat. No. 5,821,123 (Studnicka); and U.S. Pat. No. 5,869,619 (Studnicka).

Any suitable approach, including any of the above approaches, can be used to reduce or eliminate human immunogenicity of an antibody of the invention.

The antibody can be conjugated to an effector moiety such as a small molecule toxin or a radionuclide using standard in vitro conjugation chemistries. If the effector moiety is a polypeptide, the antibody can be chemically conjugated to the effector or joined to the effector as a fusion protein. Construction of fusion proteins is within ordinary skill in the art.

IV. Use of Antibodies

Antibodies disclosed herein may be engineered (e.g., humanized) for administration to humans. Antibodies disclosed herein can be used to treat various forms of cancer, e.g., breast, ovarian, prostate, cervical, colorectal, lung, pancreatic, gastric, and head and neck cancers. The cancer cells are exposed to a therapeutically effective amount of the antibody so as to inhibit or reduce proliferation of the cancer cells. In some embodiments, the antibodies inhibit cancer cell proliferation by at least 40%, 50%, 60%, 70%, 80%, 90%, 95%, 98%, 99% or 100%.

In some embodiments, the disclosed antibodies may inhibit or reduce proliferation of a tumor cell by inhibiting binding of human Notch3 to a ligand, e.g., Jag1, Jag2, DLL1, and DLL4. The disclosed antibodies can be used in a method to inhibit tumor growth in a human patient. The method comprises administering to the patient a therapeutically effective amount of the antibody.

Cancers associated with Notch3 overexpression and/or activation include, but are not limited to, breast cancer, ovarian cancer, prostate cancer, cervical cancer, lung cancer, brain cancer (e.g., glioblastoma, astrocytoma, neuroblastoma), melanomas, gastrointestinal cancers (e.g., colorectal, pancreatic, and gastric), head and neck cancer, sarcomas (e.g. rhabdomyosarcoma, osteosarcoma), and hematopoietic cell cancers, (e.g., multiple myeloma, leukemia, e.g., precursor T acute lymphoblastic leukemia (T-ALL), precursor B acute lymphoblastic leukemia (B-ALL) and B-cell chronic lymphoblastic leukemia (B-CLL)).

As used herein, “treat”, “treating” and “treatment” mean the treatment of a disease in a mammal, e.g., in a human. This includes: (a) inhibiting the disease, i.e., arresting its development; and (b) relieving the disease, i.e., causing regression of the disease state.

Generally, a therapeutically effective amount of active component is in the range of 0.1 mg/kg to 100 mg/kg, e.g., 1 mg/kg to 100 mg/kg, 1 mg/kg to 10 mg/kg. The amount administered will depend on variables such as the type and extent of disease or indication to be treated, the overall health of the patient, the in vivo potency of the antibody, the pharmaceutical formulation, and the route of administration. The initial dosage can be increased beyond the upper level in order to rapidly achieve the desired blood-level or tissue-level. Alternatively, the initial dosage can be smaller than the optimum, and the daily dosage may be progressively increased during the course of treatment. Human dosage can be optimized, e.g., in a conventional Phase I dose escalation study designed to run from 0.5 mg/kg to 20 mg/kg. Dosing frequency can vary, depending on factors such as route of administration, dosage amount, serum half-life of the antibody, and the disease being treated. Exemplary dosing frequencies are once per day, once per week and once every two weeks. A preferred route of administration is parenteral, e.g., intravenous infusion. Formulation of monoclonal antibody- based drugs is within ordinary skill in the art. In some embodiments, a monoclonal antibody is lyophilized, and then reconstituted in buffered saline, at the time of administration.

For therapeutic use, an antibody preferably is combined with a pharmaceutically acceptable carrier. As used herein, “pharmaceutically acceptable carrier” means buffers, carriers, and excipients suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit/risk ratio. The carrier(s) should be “acceptable” in the sense of being compatible with the other ingredients of the formulations and not deleterious to the recipient. Pharmaceutically acceptable carriers include buffers, solvents, dispersion media, coatings, isotonic and absorption delaying agents, and the like, that are compatible with pharmaceutical administration. The use of such media and agents for pharmaceutically active substances is known in the art.

Pharmaceutical compositions containing antibodies disclosed herein can be presented in a dosage unit form and can be prepared by any suitable method. A pharmaceutical composition should be formulated to be compatible with its intended route of administration. Examples of routes of administration are intravenous (IV), intradermal, inhalation, transdermal, topical, transmucosal, and rectal administration. A preferred route of administration for monoclonal antibodies is IV infusion. Useful formulations can be prepared by methods known in the pharmaceutical art. For example, see Remington's Pharmaceutical Sciences, 18th ed. (Mack Publishing Company, 1990). Formulation components suitable for parenteral administration include a sterile diluent such as water for injection, saline solution, fixed oils, polyethylene glycols, glycerine, propylene glycol or other synthetic solvents; antibacterial agents such as benzyl alcohol or methyl parabens; antioxidants such as ascorbic acid or sodium bisulfite; chelating agents such as EDTA; buffers such as acetates, citrates or phosphates; and agents for the adjustment of tonicity such as sodium chloride or dextrose.

For intravenous administration, suitable carriers include physiological saline, bacteriostatic water, Cremophor EL™ (BASF, Parsippany, N.J.) or phosphate buffered saline (PBS). The carrier should be stable under the conditions of manufacture and storage, and should be preserved against microorganisms. The carrier can be a solvent or dispersion medium containing, for example, water, ethanol, polyol (for example, glycerol, propylene glycol, and liquid polyetheylene glycol), and suitable mixtures thereof.

Pharmaceutical formulations preferably are sterile. Sterilization can be accomplished by any suitable method, e.g., filtration through sterile filtration membranes. Where the composition is lyophilized, filter sterilization can be conducted prior to or following lyophilization and reconstitution.

EXAMPLES

The following Examples are merely illustrative and are not intended to limit the scope or content of the invention in any way.

Example 1 Production of Anti-hNotch3 Monoclonal Antibodies

Immunizations, fusions, and primary screens were conducted using conventional methods following the Repetitive Immunization Multiple Sites (RIMMS) protocol. Five AJ mice and five Balb/c mice were immunized with a protein containing amino acids 1-428 of human Notch3 fused to the Fc portion of human IgG. In addition, five AJ and five Balb/c mice were immunized with a concatemeric protein containing two repeats of the region of Notch3 comprising EGF-like domains 9-12. From each immunization strategy, two AJ mice and 2 Balb/c mice having sera displaying high binding to immunogen by Enzyme Linked ImmunoSorbent Assay (ELISA) were chosen for subsequent fusion. Spleens and lymph nodes from the selected mice were harvested. B cells were harvested and fused with a myeloma line. Fusion products from AJ mice and Balb/c mice were serially diluted in forty 96-well plates to near clonality. A total of 5,280 supernatants from the cell fusions were screened for binding to human Notch3 on the surface of CHO cells, using a Mesoscale electrochemiluminescence assay (MSD). In total, four hundred and twenty supernatants that bound human Notch3 in this assay were identified from the AJ and Balb/c fusions. These fusion products were further characterized by in vitro biochemical and cell-based assays, as discussed below. A panel of hybridomas was selected, the hybridomas were subcloned, and monoclonal hybridomas were expanded. Antibodies were expressed from the hybridoma cell lines and purified by affinity chromatography on Protein G resin under standard conditions.

Example 2 Sequence Analysis of Anti-Notch3 Monoclonal Antibodies

The light chain isotype and heavy chain isotype of the monoclonal antibody, 4F11, in Example 1 was determined using the IsoStrip™ Mouse Monoclonal Antibody Isotyping Kit according to the manufacturer's instructions (Roche Applied Science, Indianapolis, Ind.). The antibody was determined to be kappa light chain and IgG1 heavy chain.

The heavy and light chain variable regions of the mouse monoclonal antibody were sequenced using 5′ RACE (Rapid Amplification of cDNA Ends). Total RNA was extracted from the hybridoma cell line using the RNeasy Miniprep kit according to the vendor's instructions (Qiagen, Valencia, Calif.). Full-length first strand cDNA containing 5′ ends was generated using the SMARTer™ RACE cDNA Amplification Kit (Clontech, Mountain View, Calif.) according to the manufacturer's instructions using random primers for 5′ RACE.

The variable regions of the light (kappa) and heavy (IgG1) chains were amplified by PCR, using KOD Hot Start Polymerase (EMD Chemicals, Gibbstown, N.J.) according to the manufacturer's instructions. For amplification of 5′ cDNA ends in conjunction with the SMARTer™ RACE cDNA Amplification Kit, the Universal Primer Mix A primer (Clontech), a mix of 5′CTAATACGACTCACTATAGGGCAAGCAGTGGTATCAACGCAGAGT 3′ (SEQ ID NO: 13) and 5′ CTAATACGACTCACTATAGGGC 3′ (SEQ ID NO: 17), was used as a 5′ primer. The heavy chain variable region was amplified using the above 5′ primers and a 3′ IgG1 constant region specific primer, 5′ TATGCAAGGCTTACAACCACA 3′ (SEQ ID NO: 18). The kappa chain variable region was amplified with the above 5′ primers and a 3′ kappa constant region specific primer, 5′ CGACTGAGGCACCTCCAGATGTT 3′ (SEQ ID NO: 19).

Individual PCR products were isolated by agarose gel electrophoresis and purified using the Qiaquick Gel Purification kit according to the manufacturer's instructions (Qiagen). The PCR products were subsequently cloned into the pCR®4Blunt using the Zero Blunt® TOPO® PCR Cloning Kit according to the manufacturer's instructions (Invitrogen) and transformed into DH5-α bacteria (Invitrogen) through standard molecular biology techniques. Plasmid DNA isolated from transformed bacterial clones was sequenced using M13 Forward (5′ GTAAAACGACGGCCAGT 3′) (SEQ ID NO: 21) and M13 Reverse primers (5′ CAGGAAACAGCTATGACC 3′) (SEQ ID NO: 30) by Beckman Genomics (Danvers, Mass.), using standard dideoxy DNA sequencing methods to identify the sequence of the variable region sequences. The sequences were analyzed using Vector NTI software (Invitrogen) and the IMGT/V-Quest web server (http://imgt.cines.fr) to identify and confirm variable region sequences.

The nucleic acid sequences encoding and the protein sequences defining variable regions of the murine monoclonal antibodies are summarized below (amino terminal signal peptide sequences are not shown). CDR sequences (Kabat definition) are shown in bold and are underlined in the amino acid sequences.

Nucleic Acid Sequence Encoding the Heavy Chain Variable Region of the 4F11 Antibody (SEQ ID NO: 1)

1 gaagtgcagc tggtggagtc tgggggaggc ttagtgaagc ctggagggtc cctgaaactc 61 tcctgtgcag cctctggatt cgctttcagt agctatgaca tgtcttgggt tcgccagact 121 ccggagaaga ggctggagtg ggtcgcatac attagtcgtg gtggtggtag cacctactat 181 ccagacactg tgaagggccg attcaccatc tccagagaca atgccaagaa caccctgtac 241 ctgcaaatga gcagtctgaa gtctgaggac acagccatgt attactgtgg aagacatgct 301 actacggcct actggtactt cgatgtctgg ggcgcaggga ccacggtcac cgtctcctca

Protein Sequence Defining the Heavy Chain Variable Region of the 4F11 Antibody (SEQ ID NO: 2)

1 evqlvesggg lvkpggslkl scaasgfafs sydms wvrqt pekrlewva y   isrgggstyy 61 pdtvkg rfti srdnakntly lqmsslksed tamyycgr ha   ttaywyfdv w gagttvtvss

Nucleic Acid Sequence Encoding the Kappa Chain Variable Region of the 4F11 Antibody (SEQ ID NO: 3)

1 gatgttgtga tgacccaaac tccactctcc ctgcctgtca gtcttggaga tcaagcctcc 61 atctcttgca gatctagtca gagccttgta cacactaatg gcaacaccta tttacattgg 121 tacctgcaga agccaggcca gtctccaaaa ctcctgatct acaaagtttc caaccgattt 181 tctggggtcc cagacaggtt cagtggcagt ggatcaggga cagatttcac actcaagatc 241 agcagagtgg aggctgagga tctgggagtt tatttctgct ctcaaagtac acatgttccg 301 tggacgttcg gtggaggcac caagctggaa atcaaa

Protein Sequence Defining the Kappa Chain Variable Region of the 4F11 Antibody (SEQ ID NO: 4)

1 dvvmtqtpls lpvslgdqas isc rssqslv   htngntylh w ylqkpgqspk lliy kvsnrf 61 s gvpdrfsgs gsgtdftlki srveaedlgv yfc sqsthvp   wt fgggtkle ik

Table 1 is a concordance chart showing the SEQ ID NO. of each sequence discussed in this Example.

TABLE 1 SEQ. ID NO. Nucleic Acid or Protein 1 4F11 Heavy Chain Variable Region-nucleic acid 2 4F11 Heavy Chain Variable Region-protein 3 4F11 Light (kappa) Chain Variable Region-nucleic acid 4 4F11 Light (kappa) Chain Variable Region-protein 5 4F11 Heavy Chain CDR₁ 6 4F11 Heavy Chain CDR₂ 7 4F11 Heavy Chain CDR₃ 8 4F11 Light (kappa) Chain CDR₁ 9 4F11 Light (kappa) Chain CDR₂ 10 4F11 Light (kappa) Chain CDR₃

Mouse monoclonal antibody heavy chain CDR sequences (Kabat, Chothia, and IMGT definitions) for 4F11 are shown in Table 2.

TABLE 2 CDR1 CDR2 CDR3 Kabat SYDMS YISRGGGSTYYPDTVKG HATTAYWYFDV (SEQ ID NO: 5) (SEQ ID NO: 6) (SEQ ID NO: 7) Chothia GFAFSSY SRGGGS HATTAYWYFDV (SEQ ID NO: 11) (SEQ ID NO: 12) (SEQ ID NO: 7) IMGT GFAFSSYD ISRGGGST GRHATTAYWYFDV (SEQ ID NO: 14) (SEQ ID NO: 15) (SEQ ID NO: 16)

Mouse monoclonal antibody kappa light chain CDR sequences (Kabat, Chothia, and IMGT definitions) for 4F11 are shown in Table 3.

TABLE 3 CDR1 CDR2 CDR3 Kabat/Chothia RSSQSLVHTNGNTYLH KVSNRFS SQSTHVPWT (SEQ ID NO: 8) (SEQ ID NO: 9) (SEQ ID NO: 10) IMGT QSLVHTNGNTY KVS SQSTHVPWT (SEQ ID NO: 20) (SEQ ID NO: 10)

To create the complete heavy or kappa chain antibody sequences, each variable sequence above is combined with its respective constant region. For example, a complete heavy chain comprises a heavy variable sequence followed by the murine IgG1 heavy chain constant sequence, and a complete kappa chain comprises a kappa variable sequence followed by the murine kappa light chain constant sequence.

Nucleic Acid Sequence Encoding the Murine IgG1 Heavy Chain Constant Region (SEQ ID NO: 22)

1 gccaaaacga cacccccatc tgtctatcca ctggcccctg gatctgctgc ccaaactaac 61 tccatggtga ccctgggatg cctggtcaag ggctatttcc ctgagccagt gacagtgacc 121 tggaactctg gatccctgtc cagcggtgtg cacaccttcc cagctgtcct gcagtctgac 181 ctctacactc tgagcagctc agtgactgtc ccctccagca cctggcccag cgagaccgtc 241 acctgcaacg ttgcccaccc ggccagcagc accaaggtgg acaagaaaat tgtgcccagg 301 gattgtggtt gtaagccttg catatgtaca gtcccagaag tatcatctgt cttcatcttc 361 cccccaaagc ccaaggatgt gctcaccatt actctgactc ctaaggtcac gtgtgttgtg 421 gtagacatca gcaaggatga tcccgaggtc cagttcagct ggtttgtaga tgatgtggag 481 gtgcacacag ctcagacgca accccgggag gagcagttca acagcacttt ccgctcagtc 541 agtgaacttc ccatcatgca ccaggactgg ctcaatggca aggagttcaa atgcagggtc 601 aacagtgcag ctttccctgc ccccatcgag aaaaccatct ccaaaaccaa aggcagaccg 661 aaggctccac aggtgtacac cattccacct cccaaggagc agatggccaa ggataaagtc 721 agtctgacct gcatgataac agacttcttc cctgaagaca ttactgtgga gtggcagtgg 781 aatgggcagc cagcggagaa ctacaagaac actcagccca tcatggacac agatggctct 841 tacttcgtct acagcaagct caatgtgcag aagagcaact gggaggcagg aaatactttc 901 acctgctctg tgttacatga gggcctgcac aaccaccata ctgagaagag cctctcccac 961 tctcctggta aa

Protein Sequence Defining the Murine IgG1 Heavy Chain Constant Region (SEQ ID NO: 23)

1 akttppsvyp lapgsaaqtn smvtlgclvk gyfpepvtvt wnsgslssgv htfpavlqsd 61 lytlsssvtv psstwpsetv tcnvahpass tkvdkkivpr dcgckpcict vpevssvfif 121 ppkpkdvlti tltpkvtcvv vdiskddpev qfswfvddve vhtaqtqpre eqfnstfrsv 181 selpimhqdw lngkefkcrv nsaafpapie ktisktkgrp kapqvytipp pkeqmakdkv 241 sltcmitdff peditvewqw ngqpaenykn tqpimdtdgs yfvysklnvq ksnweagntf 301 tcsvlheglh nhhtekslsh spgk

Nucleic Acid Sequence Encoding the Murine Kappa Light Chain Constant Region (SEQ ID NO: 24)

1 cgggctgatg ctgcaccaac tgtatccatc ttcccaccat ccagtgagca gttaacatct 61 ggaggtgcct cagtcgtgtg cttcttgaac aacttctacc ccaaagacat caatgtcaag 121 tggaagattg atggcagtga acgacaaaat ggcgtcctga acagttggac tgatcaggac 181 agcaaagaca gcacctacag catgagcagc accctcacgt tgaccaagga cgagtatgaa 241 cgacataaca gctatacctg tgaggccact cacaagacat caacttcacc cattgtcaag 301 agcttcaaca ggaatgagtg t

Protein Sequence Defining the Murine Kappa Light Chain Constant Region (SEQ ID NO: 25)

1 radaaptvsi fppsseqlts ggasvvcfln nfypkdinvk wkidgserqn gvlnswtdqd 61 skdstysmss tltltkdeye rhnsytceat hktstspivk sfnrnec

The following sequences represent the actual or contemplated full length heavy and light chain sequences (i.e., containing both the variable and constant regions sequences) for the 4F11 antibody described in this Example. Signal sequences for proper secretion of the antibodies (e.g., signal sequences at the 5′ end of the DNA sequences or the amino terminal end of the protein sequences) are not shown in the full length heavy and light chain sequences disclosed herein and are not included in the final secreted protein. Also not shown are stop codons for termination of translation required at the 3′ end of the DNA sequences. It is within ordinary skill in the art to select a signal sequence and/or a stop codon for expression of the disclosed full length IgG heavy chain and light chain sequences. It is also contemplated that the variable region sequences can be ligated to other constant region sequences to produce active full length IgG heavy and light chains.

Nucleic Acid Sequence Encoding the Full Length Heavy Chain Sequence (Heavy Chain Variable Region and IgG1 Constant Region) of 4F11 (SEQ ID NO: 26)

1 gaagtgcagc tggtggagtc tgggggaggc ttagtgaagc ctggagggtc cctgaaactc 61 tcctgtgcag cctctggatt cgctttcagt agctatgaca tgtcttgggt tcgccagact 121 ccggagaaga ggctggagtg ggtcgcatac attagtcgtg gtggtggtag cacctactat 181 ccagacactg tgaagggccg attcaccatc tccagagaca atgccaagaa caccctgtac 241 ctgcaaatga gcagtctgaa gtctgaggac acagccatgt attactgtgg aagacatgct 301 actacggcct actggtactt cgatgtctgg ggcgcaggga ccacggtcac cgtctcctca 361 gccaaaacga cacccccatc tgtctatcca ctggcccctg gatctgctgc ccaaactaac 421 tccatggtga ccctgggatg cctggtcaag ggctatttcc ctgagccagt gacagtgacc 481 tggaactctg gatccctgtc cagcggtgtg cacaccttcc cagctgtcct gcagtctgac 541 ctctacactc tgagcagctc agtgactgtc ccctccagca cctggcccag cgagaccgtc 601 acctgcaacg ttgcccaccc ggccagcagc accaaggtgg acaagaaaat tgtgcccagg 661 gattgtggtt gtaagccttg catatgtaca gtcccagaag tatcatctgt cttcatcttc 721 cccccaaagc ccaaggatgt gctcaccatt actctgactc ctaaggtcac gtgtgttgtg 781 gtagacatca gcaaggatga tcccgaggtc cagttcagct ggtttgtaga tgatgtggag 841 gtgcacacag ctcagacgca accccgggag gagcagttca acagcacttt ccgctcagtc 901 agtgaacttc ccatcatgca ccaggactgg ctcaatggca aggagttcaa atgcagggtc 961 aacagtgcag ctttccctgc ccccatcgag aaaaccatct ccaaaaccaa aggcagaccg 1021 aaggctccac aggtgtacac cattccacct cccaaggagc agatggccaa ggataaagtc 1081 agtctgacct gcatgataac agacttcttc cctgaagaca ttactgtgga gtggcagtgg 1141 aatgggcagc cagcggagaa ctacaagaac actcagccca tcatggacac agatggctct 1201 tacttcgtct acagcaagct caatgtgcag aagagcaact gggaggcagg aaatactttc 1261 acctgctctg tgttacatga gggcctgcac aaccaccata ctgagaagag cctctcccac 1321 tctcctggta aa

Protein Sequence Defining the Full Length Heavy Chain Sequence (Heavy Chain Variable Region and IgG1 Constant Region) of 4F11 (SEQ ID NO: 27)

1 evqlvesggg lvkpggslkl scaasgfafs sydmswvrqt pekrlewvay isrgggstyy 61 pdtvkgrfti srdnakntly lqmsslksed tamyycgrha ttaywyfdvw gagttvtvss 121 akttppsvyp lapgsaaqtn smvtlgclvk gyfpepvtvt wnsgslssgv htfpavlqsd 181 lytlsssvtv psstwpsetv tcnvahpass tkvdkkivpr dcgckpcict vpevssvfif 241 ppkpkdvlti tltpkvtcvv vdiskddpev qfswfvddve vhtaqtqpre eqfnstfrsv 301 selpimhqdw lngkefkcrv nsaafpapie ktisktkgrp kapqvytipp pkeqmakdkv 361 sltcmitdff peditvewqw ngqpaenykn tqpimdtdgs yfvysklnvq ksnweagntf 421 tcsvlheglh nhhtekslsh spgk

Nucleic Acid Sequence Encoding the Full Length Light Chain Sequence (Kappa Chain Variable Region and Constant Region) of 4F11 (SEQ ID NO: 28)

1 gatgttgtga tgacccaaac tccactctcc ctgcctgtca gtcttggaga tcaagcctcc 61 atctcttgca gatctagtca gagccttgta cacactaatg gcaacaccta tttacattgg 121 tacctgcaga agccaggcca gtctccaaaa ctcctgatct acaaagtttc caaccgattt 181 tctggggtcc cagacaggtt cagtggcagt ggatcaggga cagatttcac actcaagatc 241 agcagagtgg aggctgagga tctgggagtt tatttctgct ctcaaagtac acatgttccg 301 tggacgttcg gtggaggcac caagctggaa atcaaacggg ctgatgctgc accaactgta 361 tccatcttcc caccatccag tgagcagtta acatctggag gtgcctcagt cgtgtgcttc 421 ttgaacaact tctaccccaa agacatcaat gtcaagtgga agattgatgg cagtgaacga 481 caaaatggcg tcctgaacag ttggactgat caggacagca aagacagcac ctacagcatg 541 agcagcaccc tcacgttgac caaggacgag tatgaacgac ataacagcta tacctgtgag 601 gccactcaca agacatcaac ttcacccatt gtcaagagct tcaacaggaa tgagtgt

Protein Sequence Defining the Full Length Light Chain Sequence (Kappa Chain Variable Region and Constant Region) of 4F11 (SEQ ID NO: 29)

1 dvvmtqtpls lpvslgdqas iscrssqslv htngntylhw ylqkpgqspk lliykvsnrf 61 sgvpdrfsgs gsgtdftlki srveaedlgv yfcsqsthvp wtfgggtkle ikradaaptv 121 sifppsseql tsggasvvcf lnnfypkdin vkwkidgser qngvlnswtd qdskdstysm 181 sstltltkde yerhnsytce athktstspi vksfnrnec

Table 4 is a concordance chart showing the correspondence between the full length sequences of the antibodies discussed in this Example with those presented in the Sequence Listing.

TABLE 4 SEQ ID NO. Nucleic Acid or Protein 26 4F11 Heavy Variable + IgG1 Constant-nucleic acid 27 4F11 Heavy Variable + IgG1 Constant-protein 28 4F11 Kappa Variable + Constant-nucleic acid 29 4F11 Kappa Variable + Constant-protein

Example 3 Binding Affinities

The binding affinity and kinetics of binding of antibody 4F11 to recombinant human Notch3 extracellular domain (containing EGF like domains 1-11) Fc fusion protein (rhNotch3-Fc (R&D Systems, Inc., Minneapolis, Minn.)) were measured by surface plasmon resonance using a Biacore® T100 instrument (GE Healthcare, Piscataway, N.J.).

Rabbit anti-mouse IgGs (GE Healthcare) were immobilized on carboxymethylated dextran CM4 sensor chips (GE Healthcare) by amine coupling, according to a standard protocol. Analyses were performed at 25° C. and 37° C. using PBS containing 0.05% surfactant P20 as running buffer. The antibody was captured in individual flow cells at a flow rate of 10 μl/minute. Injection time was varied for each antibody to yield an Rmax between 30 and 60 resonance units (RU). Buffer or rhNotch3-Fc diluted in running buffer was injected sequentially over a reference surface (no antibody captured) and the active surface (antibody to be tested) for 240 seconds at 60 μl/minute. The dissociation phase was monitored for up to 1500 seconds. The surface was then regenerated with two 60-second injections of 10 mM Glycine-HCl, pH 2.25, at a flow rate of 30 μl/minute. The rhNotch3-Fc concentration range tested was 100 nM to 3.125 nM (2 fold dilution).

Kinetic parameters were determined using the kinetic function of the BIAevaluation software (GE Healthcare) with double reference subtraction. Kinetic parameters for the antibody, k_(a) (association rate constant), k_(d) (dissociation rate constant) and K_(D) (equilibrium dissociation constant) were determined Kinetic values of the monoclonal antibody 4F11 on rhNotch3-Fc at 25° C. and 37° C. are summarized in Table 5.

TABLE 5 Antibody Binding to rhNotch3-Fc Temperature k_(a) (1/Ms) k_(d) (1/s) K_(D) (M) n 25° C. 7.0E+04 4.8E−05 8.23E−10 3 37° C. 7.5E+04 5.7E−05  7.8E−10 3

The data in Table 5 demonstrate that the antibody 4F11 binds rhNotch3-Fc with a K_(D) of about 1 nM, 900 pM, 850 pM, 800 pM, 750 pM, 700 pM, 650 pM, 600 pM, 500 pM, 400 pM, 300 pM, 250 pM, or 200 pM or less.

Binding to cell surface human Notch3 by the antibody 4F11 was measured at 4° C., using Fluorescence Activated Cell Sorting (FACS). CHO N3 (Flp-In-CHO cells (Invitrogen) stably transfected with human Notch3), HCC2429 cells, and RL-952 cells expressing human Notch3 were washed once with PBS containing calcium chloride and magnesium chloride (Invitrogen) and harvested using cell dissociation buffer (Invitrogen). Cells were washed a second time with PBS and resuspended in FACS buffer (PBS with 0.5% BSA (Sigma-Aldrich)) for a final cell concentration of 250,000 cells per well into a 96-well v-bottom plate. Purified antibodies were diluted in FACS buffer over a concentration range of 100 nM to 0.1 nM. Cells were then incubated at 4° C. with 100 μl of antibody for one hour, washed with FACS buffer twice, and resuspended in 100 μl of goat-anti mouse PE-conjugated antibody (Jackson Immuno Research). Cells were incubated at 4° C. for 30 minutes in the dark, washed once with FACS buffer, and then analyzed using a Beckman Coulter Cytomics FC 500 instrument. The geometric mean of the florescent intensity was then calculated for each antibody concentration. These values were then entered into Prism software (GraphPad, La Jolla, Calif.) and used to generate a binding curve by plotting geometric mean versus antibody concentration. From the binding curve, the following equation was used to calculate the K_(D) and K_(D) range of 4F11 binding to human Notch3 on the cell surface of the three cell lines.

Equation: One Site Binding (Hyperbola)

Y=B _(max) *X/(K _(D) +X)

*describes the binding of a ligand to a receptor that follows the law of mass action. B_(max) is the maximal binding, and K_(D) is the concentration of ligand required to reach half-maximal binding.

Results are summarized in Table 6.

TABLE 6 K_(D) (nM) K_(D) Range (nM) CH0 N3 0.36 0.21 to 0.51 HCC2429 2.58 1.21 to 3.95 RL-952 0.9633 0.7168 to 1.210 

The results in Table 6 demonstrate that the antibody 4F11 binds cell surface Notch3 with a K_(D) of about 1 nM, 750 pM, 650 pM, 600 pM, 500 pM, 400 pM, 300 pM, 250 pM, or 200 pM or less.

Example 4 Binding Specificity

Antibody 4F11 was tested for binding to human Notch1, human Notch2, or human Notch3 proteins. Binding measurements were made by biolayer interferometry (BLI), using a ForteBio Octet® QK instrument (ForteBio, Menlo Park, Calif.). Anti-human-Fc sensors were soaked in PBS containing 1 mg/ml BSA for five minutes prior to binding of antibodies. Then the following proteins (400 nM, in PBS containing 1 mg/ml BSA) were allowed to bind to the sensors: rhNotch1-Fc (R&D Systems, Minneapolis, Minn.; Cat. No. 3647-TK-050), rhNotch2-Fc (R&D Cat. No. 3735-NT-050), rhNotch3-Fc (R&D Cat. No. 1559-NT-050), or rmNotch3-Fc (R&D Cat. No. 1308-NT-050). Notch protein bound sensors were immersed in antibody solution (50 ng/ml) to allow binding of antibody to the Notch protein. Binding was detected by shifts in the interference pattern. These results demonstrated that the antibodies bind specifically to human Notch3 protein, but do not bind to human Notch2 or human Notch1 protein (FIG. 4).

Stable cells lines expressing Notch receptors were produced by transfecting FlpIn™ CHO or FlpIn™ 293 cells (Life Technologies, Grand Island, N.Y.) with full length human Notch1, Notch2, Notch3, or Notch4 cDNAs cloned into the pcDNASFRT vector using Lipofectamine 2000 (Life Technologies) according to the manufacturer's protocol. Twenty-four hours after transfection, CHO cells were split into F12 media containing 10% FBS, 2 mM L-Glutamine and 700 ng/ml hygromycin B (Sigma-Aldrich, St. Louis, Mo.) to select for transfected cells. 293 cells were split into DMEM media containing 10% FBS, 2 mM L-glutamine and 200 ng/ml hygromycin B. Expression of Notch receptors was confirmed by FACS analysis using anti-human Notch1 PE (BioLegend, San Diego, Calif.), anti-Notch2 PE (eBioscience, San Diego, Calif.), or anti-human Notch3 PE (BioLegend, San Diego, Calif.).

To determine specificity of binding to cell surface Notch proteins, antibody 4F11 was tested for binding to human Notch1, human Notch2, human Notch3 and human Notch4 expressed on the surface of CHO cells using electrochemiluminescence (Meso Scale Discovery). A CHO line lacking any human Notch protein was also produced for use as a negative control. Cells were grown under standard conditions (37° C., F12+10% FBS). For binding studies, cells were washed in PBS containing calcium and magnesium, and removed from the plate by treatment with Cell Dissociation Buffer (Life Technologies) for ten minutes at 37° C.

Cells were seeded at a density of 30,000 cells per well, in hybridoma media, instandard 96-well binding plates (Meso Scale Discovery, Cat. No. L15XA-6). Cells were incubated for one hour at 37° C. Antibodies or control IgG were added at 5 μg/ml, in 50 μl hybridoma media, and incubated for one hour at 37° C. The plates were washed twice with PBS containing 3% BSA. Binding of the antibodies to cell surface was detected using 2 μg/ml of MSD anti-mouse IgG secondary antibody (Meso Scale Discovery, Cat. No. R32AC-1) for one hour at 4° C. Plates were washed twice with PBS containing 3% BSA, and 150 μl of read buffer (Meso Scale Discovery Cat. No. R92TC-1) was added. The plates were analyzed on a Sector Imager 2400 instrument (Meso Scale Discovery). This analysis showed that antibody 4F11 binds to human Notch3 displayed on the surfaces of cells, but does not bind to human Notch1, Notch2, or Notch4 displayed on the surfaces of cells. The 4F11 antibody also does not bind CHO-EV (empty vector) cells that express endogenous hamster Notch proteins. These results indicated that antibody 4F11 binds specifically to human Notch3 protein displayed on a cell surface in vitro.

Example 5 Inhibition of Notch3-Ligand Binding

The 4F11 antibody was tested for its ability to inhibit the binding of rhNotch3 binding to human Jag1, Jag2, DLL1 and DLL4. Binding measurements were made by bio-layer interferometry (BLI), using a ForteBio Octet® QK instrument (ForteBio, Menlo Park, Calif.). The ligands tested were rhJag1-Fc (R&D Cat. No. 1277-JG-050), rhJag2-Fc (R&D Cat. No. 1726-JG-050), rhDLL1-Fc (R&D Cat. No. 5026-DL-050), and His tagged rhDLL4 (R&D Cat. No. 1506-D4-050).

To determine the degree of inhibition of Notch3-ligand binding by antibody 4F11, the Octet sensors were loaded with recombinant human Notch3, and the antibody was allowed to bind, as described in Example 4. In positive control samples, a commercially available Notch3 polyclonal antibody capable of blocking ligand binding to recombinant human Notch3 (Notch3 Specific Control) was used instead of the 4F11 antibody. Then sensors were immersed in 500 μg/ml human IgG, to block non-specific binding. Ligands were prepared at a concentration of 400 nM in PBS containing 3% BSA, and were allowed to bind. The on-rate and off-rate for ligand binding were detected using the Octet QK instrument and software. The 4F11 antibody blocked binding of all four ligands to rhNotch3-Fc (FIG. 5A-5D).

Example 6 Inhibition of Ligand-Induced Notch3 ICD Cleavage

Activation of Notch receptors results in cleavage of the Notch intracellular domain (NICD), which can be detected by Western blot. The effect of antibody 4F11 on the activation of Notch3 ICD cleavage was tested.

To create soluble Notch ligands, PCR was used to amplify sequences corresponding to the extracellular domains of human Jag1 or human Jag2 cDNA and fuse them in-frame to the coding sequence of human IgG Fc. This construct was then subcloned into the pEE14.4 expression vector (Lonza), transfected into CHOK1SV cells, and selected to produce stable cell lines that secrete hJag1-hFc or hJag2-hFc fusion protein. 96-well Immunosorp ELISA plates (Nalgene Nunc, Rochester, N.Y.) were coated with 5 μg/ml anti-human Fc (Jackson ImmunoResearch, West Grove, Pa.) overnight at 4° C. After washing wells with PBS/0.5% BSA, 5 μg/ml of soluble hJag 1-hFc fusion protein was added and allowed to bind at room temperature for two hours. Unbound protein was removed by washing with PBS/0.5% BSA. FlpIn™ 293 cells engineered to express hNotch3 (as described in Example 4) were plated on Jag1-hFc ligand or hFc in the presence of 10 μg/ml 4F11 or mIgG control antibody. Cells were lysed 24 hours later in RIPA buffer (Boston BioProducts, Ashland, Mass.) containing protease inhibitors. Induction of cleaved NICD was detected by probing the blot with a Notch3 antibody against the C-terminus (Cell Signaling, Danvers, Mass.) that detects both full length protein and the cleaved ICD. Ligand-induced activation and Notch3 ICD cleavage was inhibited by antibody 4F11.

Example 7 Inhibition of Notch3-Dependent Transcription

Reporter cell lines dependent upon Notch3 were produced by lentiviral introduction of a RBP-Jκ-dependent luciferase reporter gene (SABiosciences, Frederick, Md.) into 293-FlpIn Notch3 cells, RL95-2 endometrial cancer cells, HCC1143 breast cancer cells, and MDA-MB-468 breast cancer cells. To activate Notch3-dependent signaling and transcription, cells were plated on ligand-coated wells prepared as described in Example 6. Cells were pre-incubated with a 3-fold dilution series of Notch3 antibody concentrations ranging from 0-300 μg/ml, for one hour at 37° C., before seeding 100 μl of the suspension into 96-well plates coated with ligand or hFc. Cells were incubated in ligand-coated or human-Fc-coated wells for four or twenty-four hours at 37° C., in 5% CO₂. Next, 100 μl of Promega Bright Glo™ (Promega, Madison, Wis.) was added to each well. The reaction was allowed to proceed for five minutes in the dark, and then the entire 200 μl volume was transferred to white walled plates and read using a luminometer. Polyclonal antibodies against Notch1 (AF1057, R&D Systems), Notch2 (AF1190, R&D Systems) or Notch3 (AF1559, R&D Systems) were used as controls to confirm that ligand-stimulated reporter activity in each cell line was specifically dependent upon the introduced Notch receptor. As shown in FIG. 6A, Notch3 antibody 4F11 inhibited Notch3-dependent transcription stimulated by the ligand Jag2. Activation of Notch3-dependent transcription by each of the ligands Jag1, Jag2, DLL1, and DLL4 was also inhibited by the Notch3 antibody 4F11 (FIG. 6B and Table 7).

TABLE 7 Ligand Jag1 Jag2 DLL1 DLL4 EC₅₀ 2.6 nM 0.4 nM 6.0 nM 4.7 nM Maximum 92% 99% 100% 73% Inhibition

Example 8 Humanization of Anti-Notch3 Antibodies

This Example describes the humanization and chimerization of the anti-human Notch3 antibody 4F11, and the characterization of the resulting humanized antibodies. The humanized anti-Notch3 antibodies were designed, affinity matured by targeted CDR mutagenesis, and optimized using methods known in the art. The amino acid sequences were converted to codon-optimized DNA sequences and synthesized to include (in the following order): 5′ HindIII restriction site, Kozak consensus sequence, amino terminal signal sequence, humanized variable region, human IgG1 or Kappa constant region, stop codon, and a 3′ EcoRI restriction site.

Chimeric (murine variable region and human constant region) 4F11 heavy (human IgG1) and light (human Kappa) chains were also constructed. To generate chimeric antibodies, the murine variable regions were fused to the human constant region, and codon-optimized DNA sequences were synthesized, including (in the following order): 5′ HindIII restriction site, Kozak consensus sequence, amino terminal signal sequence, mouse variable region, human IgG1 or Kappa constant region, stop codon, and 3′ EcoRI restriction site.

The humanized and chimeric heavy chains were subcloned into pEE6.4 (Lonza, Basel, Switzerland) via HindIII and EcoRI sites using In-Fusion™ PCR cloning (Clontech, Mountain View, Calif.). The humanized and chimeric Kappa light chains were subcloned into pEE14.4 (Lonza) via HindIII and EcoRI sites using In-Fusion™ PCR cloning.

Humanized antibody chains or chimeric antibody chains were transiently transfected into 293T cells to produce antibody. Antibody was either purified or used in cell culture media supernatant for subsequent in vitro analysis. Binding of the chimeric and humanized antibodies to Notch3 was measured as described below. The results are summarized in Tables 14-16.

Exemplary combinations of the chimeric or humanized 4F11 immunoglobulin heavy chain and immunoglobulin light chain variable regions is set forth below in Table 8.

TABLE 8 Antibody Heavy Chain Variable Light Chain Variable Name Region Region Hu4F11-1 Ch4F11 Chimeric Heavy Ch4F11 Chimeric Kappa (SEQ ID NO: 2) (SEQ ID NO: 4) Hu4F11-10 Sh4F11 Hv3-23 Heavy Ch4F11 Chimeric Kappa (SEQ ID NO: 34) (SEQ ID NO: 4) Hu4F11-18 Ch4F11 Chimeric Heavy Hu4F11 Kv2D-29 Kappa (SEQ ID NO: 2) (SEQ ID NO: 44) Hu4F11-32 Sh4F11 Hv3-23 Heavy Hu4F11 Kv2D-29 Kappa (SEQ ID NO: 34) (SEQ ID NO: 44) Hu4F11-69 Sh4F11 Hv3-23 A28T S31N Hu4F11 Kv2D-29 N28H T62S Heavy Kappa (SEQ ID NO: 40) (SEQ ID NO: 46) Hu4F11-70 Sh4F11 Hv3-23 A28T S31H Hu4F11 Kv2D-29 N28H T62S Heavy Kappa (SEQ ID NO: 36) (SEQ ID NO: 46) Hu4F11-71 Sh4F11 Hv3-23 A28T Hu4F11 Kv2D-29 N28H T62S Heavy Kappa (SEQ ID NO: 42) (SEQ ID NO: 46) Hu4F11-72 Sh4F11 Hv3-23 S31H Hu4F11 Kv2D-29 N28H T62S Heavy Kappa (SEQ ID NO: 38) (SEQ ID NO: 46) Hu4F11-73 Sh4F11 Hv3-23 A28T S31N Hu4F11 Kv2D-29 N28Y T62S Heavy Kappa (SEQ ID NO: 40) (SEQ ID NO: 50) Hu4F11-74 Sh4F11 Hv3-23 A28T S31H Hu4F11 Kv2D-29 N28Y T62S Heavy Kappa (SEQ ID NO: 36) (SEQ ID NO: 50) Hu4F11-75 Sh4F11 Hv3-23 A28T Hu4F11 Kv2D-29 N28Y T62S Heavy Kappa (SEQ ID NO: 42) (SEQ ID NO: 50) Hu4F11-76 Sh4F11 Hv3-23 S31H Hu4F11 Kv2D-29 N28Y T62S Heavy Kappa (SEQ ID NO: 38) (SEQ ID NO: 50) Hu4F11-77 Sh4F11 Hv3-23 A28T S31N Hu4F11 Kv2D-29 N28Q T62S Heavy Kappa (SEQ ID NO: 40) (SEQ ID NO: 48) Hu4F11-78 Sh4F11 Hv3-23 A28T S31H Hu4F11 Kv2D-29 N28Q T62S Heavy Kappa (SEQ ID NO: 36) (SEQ ID NO: 48) Hu4F11-79 Sh4F11 Hv3-23 A28T Hu4F11 Kv2D-29 N28Q T62S Heavy Kappa (SEQ ID NO: 42) (SEQ ID NO: 48) Hu4F11-80 Sh4F11 Hv3-23 S31H Hu4F11 Kv2D-29 N28Q T62S Heavy Kappa (SEQ ID NO: 38) (SEQ ID NO: 48)

The nucleic acid sequences and the encoded protein sequences defining variable regions of the chimeric and humanized 4F11 antibodies are summarized below (amino terminal signal peptide sequences are not shown). CDR sequences (Kabat definition) are shown in bold and are underlined in the amino acid sequences.

Nucleic Acid Sequence Encoding the Ch4F11 Chimeric Heavy Chain Variable Region (SEQ ID NO:31)

1 gaggtacagc ttgtcgagtc gggaggagga ttggtaaaac cgggtgggtc actcaaattg 61 tcgtgtgcgg cgtcgggatt tgcgttttcg tcgtatgata tgtcgtgggt gcgccagacg 121 ccggaaaaac gattggaatg ggtcgcgtat atctcccgag ggggaggttc gacatactat 181 cccgacacgg tcaaagggcg cttcacgatt tcacgggaca atgcgaaaaa cacgctttat 241 cttcaaatgt cgtcgttgaa atcggaagat accgcgatgt attactgcgg gaggcatgcg 301 acgacggcgt attggtattt cgatgtgtgg ggagccggaa cgacggtgac ggtgtcgtcg

Protein Sequence Defining the Ch4F11 Chimeric Heavy Chain Variable Region (SEQ ID NO:2)

1 evqlvesggg lvkpggslkl scaasgfafs sydms wvrqt pekrlewva y   isrgggstyy 61 pdtvkg rfti srdnakntly lqmsslksed tamyycgr ha   ttaywyfdv w gagttvtvss

Nucleic Acid Sequence Encoding the Sh4F11 Hv3-23 Heavy Chain Variable Region (SEQ ID NO:33)

1 gaagtacagt tgttggagtc aggaggaggg ttggtccagc cgggtggatc gttgcggctt 61 tcgtgtgcgg cgtcgggatt cgcgttttca tcgtatgaca tgtcgtgggt gaggcaggca 121 ccggggaaag ggcttgaatg ggtatcgtac atttcgagag ggggaggatc gacgtattac 181 ccggatacgg tgaaaggaag gtttacgatc tcgcgcgaca attcaaagaa tacgctttat 241 cttcagatga actcgctccg agcggaagat acggcggtat actattgcgg tcgccatgcg 301 acgacggcgt attggtattt cgatgtgtgg ggacaaggga cgatggtcac ggtgtcgtcg

Protein Sequence Defining the Sh4F11 Hv3-23 Heavy Chain Variable Region (SEQ ID NO:34)

1 evqllesggg lvqpggslrl scaasgfafs sydms wvrqa pgkglewvs y   isrgggstyy 61 pdtvkg rfti srdnskntly lqmnslraed tavyycgr ha   ttaywyfdv w gqgtmvtvss

Nucleic Acid Sequence Encoding the Sh4F11 Hv3-23 A28T S31H T62S Heavy Chain Variable Region (SEQ ID NO:35)

1 gaagtacagt tgttggagtc aggaggaggg ttggtccagc cgggtggatc gttgcggctt 61 tcgtgtgcgg cgtcgggatt caccttttca cactatgaca tgtcgtgggt gaggcaggca 121 ccggggaaag ggcttgaatg ggtatcgtac atttcgagag ggggaggatc gacgtattac 181 ccggattccg tgaaaggaag gtttacgatc tcgcgcgaca attcaaagaa tacgctttat 241 cttcagatga actcgctccg agcggaagat acggcggtat actattgcgg tcgccatgcg 301 acgacggcgt attggtattt cgatgtgtgg ggacaaggga cgatggtcac ggtgtcgtcg

Protein Sequence Defining the Sh4F11 Hv3-23 A28T S31H T62S Heavy Chain Variable Region (SEQ ID NO:36)

1 evqllesggg lvqpggslrl scaasgftfs hydms wvrqa pgkglewvs y   isrgggstyy 61 pdsvkg rfti srdnskntly lqmnslraed tavyycgr ha   ttaywyfdv w gqgtmvtvss

Nucleic Acid Sequence Encoding the Sh4F11 Hv3-23 S31H T62S Heavy Chain Variable Region (SEQ ID NO:37)

1 gaagtacagt tgttggagtc aggaggaggg ttggtccagc cgggtggatc gttgcggctt 61 tcgtgtgcgg cgtcgggatt cgcgttttca cactatgaca tgtcgtgggt gaggcaggca 121 ccggggaaag ggcttgaatg ggtatcgtac atttcgagag ggggaggatc gacgtattac 181 ccggattccg tgaaaggaag gtttacgatc tcgcgcgaca attcaaagaa tacgctttat 241 cttcagatga actcgctccg agcggaagat acggcggtat actattgcgg tcgccatgcg 301 acgacggcgt attggtattt cgatgtgtgg ggacaaggga cgatggtcac ggtgtcgtcg

Protein Sequence Defining the Sh4F11 Hv3-23 S31H T62S Heavy Chain Variable Region (SEQ ID NO:38)

1 evqllesggg lvqpggslrl scaasgfafs hydms wvrqa pgkglewvs y   isrgggstyy 61 pdsvkg rfti srdnskntly lqmnslraed tavyycgr ha   ttaywyfdv w gqgtmvtvss

Nucleic Acid Sequence Encoding the Sh4F11 Hv3-23 A28T S31N T62S Heavy Chain Variable Region (SEQ ID NO:39)

1 gaagtacagt tgttggagtc aggaggaggg ttggtccagc cgggtggatc gttgcggctt 61 tcgtgtgcgg cgtcgggatt caccttttca aactatgaca tgtcgtgggt gaggcaggca 121 ccggggaaag ggcttgaatg ggtatcgtac atttcgagag ggggaggatc gacgtattac 181 ccggattccg tgaaaggaag gtttacgatc tcgcgcgaca attcaaagaa tacgctttat 241 cttcagatga actcgctccg agcggaagat acggcggtat actattgcgg tcgccatgcg 301 acgacggcgt attggtattt cgatgtgtgg ggacaaggga cgatggtcac ggtgtcgtcg

Protein Sequence Defining the Sh4F11 Hv3-23 A28T S31N T62S Heavy Chain Variable Region (SEQ ID NO:40)

1 evqllesggg lvqpggslrl scaasgftfs nydms wvrqa pgkglewvs y   isrgggstyy 61 pdsvkg rfti srdnskntly lqmnslraed tavyycgr ha   ttaywyfdv w gqgtmvtvss

Nucleic Acid Sequence Encoding the Sh4F11 Hv3-23 A28T T62S Heavy Chain Variable Region (SEQ ID NO:41)

1 gaagtacagt tgttggagtc aggaggaggg ttggtccagc cgggtggatc gttgcggctt 61 tcgtgtgcgg cgtcgggatt caccttttca tcgtatgaca tgtcgtgggt gaggcaggca 121 ccggggaaag ggcttgaatg ggtatcgtac atttcgagag ggggaggatc gacgtattac 181 ccggattccg tgaaaggaag gtttacgatc tcgcgcgaca attcaaagaa tacgctttat 241 cttcagatga actcgctccg agcggaagat acggcggtat actattgcgg tcgccatgcg 301 acgacggcgt attggtattt cgatgtgtgg ggacaaggga cgatggtcac ggtgtcgtcg

Protein Sequence Defining the Sh4F11 Hv3-23 A28T T62S Heavy Chain Variable Region (SEQ ID NO:42)

1 evqllesggg lvqpggslrl scaasgftfs sydms wvrqa pgkglewvs y   isrgggstyy 61 pdsvkg rfti srdnskntly lqmnslraed tavyycgr ha   ttaywyfdv w gqgtmvtvss

Nucleic Acid Sequence Encoding the Ch4F11 Chimeric Kappa Chain Variable Region (SEQ ID NO:32)

1 gacgtggtaa tgacgcagac gccgttgtcc cttcctgtct cgctcggaga tcaggcgtcg 61 atctcgtgta gaagctcgca gtcactcgtc cataccaacg ggaatacata tcttcactgg 121 tatttgcaaa agcccggaca gtcaccgaag ctcttgatct acaaagtatc caatcggttt 181 tcgggggtgc ccgaccgatt ctcgggatcg ggttcgggga cggattttac gttgaagatt 241 tcgcgggtgg aagcggagga tctcggtgtc tacttttgtt cgcagtcaac gcatgtcccg 301 tggacgttcg gaggcgggac aaaacttgag atcaag

Protein Sequence Defining the Ch4F11 Chimeric Kappa Chain Variable Region (SEQ ID NO:4)

1 dvvmtqtpls lpvslgdqas isc rssqslv   htngntylh w ylqkpgqspk lliy kvsnrf 61 s gvpdrfsgs gsgtdftlki srveaedlgv yfc sqsthvp   wt fgggtkle ik

Nucleic Acid Sequence Encoding the Hu4F11 Kv2D-29 Kappa Chain Variable Region (SEQ ID NO:43)

1 gatgtagtca tgacccaaac gccgctttcg ttgtcggtga cgcccggaca gcccgcgtca 61 atctcgtgtc ggtcatcgca gtcgttggta cacacaaacg gtaatacgta tctccattgg 121 tatctccaga agcccggcca gtcgccgcag ctcttgatct acaaagtgag caatcgcttt 181 tcgggggtgc cggatcggtt ctcgggatcg gggtcaggaa cggacttcac gcttaagatt 241 tcgagggtcg aggcggagga tgtcggagtc tacttttgtt cgcagtccac acatgtcccc 301 tggacgtttg ggcaggggac gaaggtggaa atcaag

Protein Sequence Defining the Hu4F11 Kv2D-29 Kappa Chain Variable Region (SEQ ID NO:44)

1 dvvmtqtpls lsvtpgqpas isc rssqslv   htngntylh w ylqkpgqspq lliy kvsnrf 61 s gvpdrfsgs gsgtdftlki srveaedvgv yfc sqsthvp   wt fgqgtkve ik

Nucleic Acid Sequence Encoding the Hu4F11 Kv2D-29 N28H Kappa Chain Variable Region (SEQ ID NO:45)

1 gatgtagtca tgacccaaac gccgctttcg ttgtcggtga cgcccggaca gcccgcgtca 61 atctcgtgtc ggtcatcgca gtcgttggta cacacacacg gtaatacgta tctccattgg 121 tatctccaga agcccggcca gtcgccgcag ctcttgatct acaaagtgag caatcgcttt 181 tcgggggtgc cggatcggtt ctcgggatcg gggtcaggaa cggacttcac gcttaagatt 241 tcgagggtcg aggcggagga tgtcggagtc tacttttgtt cgcagtccac acatgtcccc 301 tggacgtttg ggcaggggac gaaggtggaa atcaag

Protein Sequence Defining the Hu4F11 Kv2D-29 N28H Kappa Chain Variable Region (SEQ ID NO:46)

1 dvvmtqtpls lsvtpgqpas isc rssqslv   hthgntylh w ylqkpgqspq lliy kvsnrf 61 s gvpdrfsgs gsgtdftlki srveaedvgv yfc sqsthvp   wt fgqgtkve ik

Nucleic Acid Sequence Encoding the Hu4F11 Kv2D-29 N28Q Kappa Chain Variable Region (SEQ ID NO:47)

1 gatgtagtca tgacccaaac gccgctttcg ttgtcggtga cgcccggaca gcccgcgtca 61 atctcgtgtc ggtcatcgca gtcgttggta cacacacaag gtaatacgta tctccattgg 121 tatctccaga agcccggcca gtcgccgcag ctcttgatct acaaagtgag caatcgcttt 181 tcgggggtgc cggatcggtt ctcgggatcg gggtcaggaa cggacttcac gcttaagatt 241 tcgagggtcg aggcggagga tgtcggagtc tacttttgtt cgcagtccac acatgtcccc 301 tggacgtttg ggcaggggac gaaggtggaa atcaag

Protein Sequence Defining the Hu4F11 Kv2D-29 N28Q Kappa Chain Variable Region (SEQ ID NO:48)

1 dvvmtqtpls lsvtpgqpas isc rssqslv   htqgntylh w ylqkpgqspq lliy kvsnrf 61 s gvpdrfsgs gsgtdftlki srveaedvgv yfc sgsthvp   wt fgqgtkve ik

Nucleic Acid Sequence Encoding the Hu4F11 Kv2D-29 N28Y Kappa Chain Variable Region (SEQ ID NO:49)

1 gatgtagtca tgacccaaac gccgctttcg ttgtcggtga cgcccggaca gcccgcgtca 61 atctcgtgtc ggtcatcgca gtcgttggta cacacatacg gtaatacgta tctccattgg 121 tatctccaga agcccggcca gtcgccgcag ctcttgatct acaaagtgag caatcgcttt 181 tcgggggtgc cggatcggtt ctcgggatcg gggtcaggaa cggacttcac gcttaagatt 241 tcgagggtcg aggcggagga tgtcggagtc tacttttgtt cgcagtccac acatgtcccc 301 tggacgtttg ggcaggggac gaaggtggaa atcaag

Protein Sequence Defining the Hu4F11 Kv2D-29 N28Y Kappa Chain Variable Region (SEQ ID NO:50)

1 dvvmtqtpls lsvtpgqpas isc rssqslv   htygntylh w ylqkpgqspq lliy kvsnrf 61 s gvpdrfsgs gsgtdftlki srveaedvgv yfc sqsthv p wt fgqgtkve ik

The amino acid sequences defining the immunoglobulin heavy chain variable regions for the antibodies produced in Example 8 are aligned in FIG. 7 Amino terminal signal peptide sequences (for proper expression/secretion) are not shown. CDR₁, CDR₂, and CDR₃ (Kabat definition) are identified by boxes. FIG. 8 show an alignment of the separate CDR₁, CDR₂, and CDR₃ sequences for each of the variable region sequences shown in FIG. 7.

The amino acid sequences defining the immunoglobulin light chain variable regions for the antibodies in Example 8 are aligned in FIG. 9. Amino terminal signal peptide sequences (for proper expression/secretion) are not shown. CDR₁, CDR₂ and CDR₃ are identified by boxes. FIG. 10 shows an alignment of the separate CDR₁, CDR₂, and CDR₃ sequences for each of the variable region sequences shown in FIG. 9.

Table 9 is a concordance chart showing the SEQ ID NO. of each sequence discussed in this Example.

TABLE 9 SEQ. ID NO. Nucleic Acid or Protein 31 Ch4F11 Chimeric Heavy Chain Variable Region-nucleic acid 2 Ch4F11 Chimeric Heavy Chain Variable Region-protein 5 Ch4F11 Chimeric Heavy Chain CDR₁ 6 Ch4F11 Chimeric Heavy Chain CDR₂ 7 Ch4F11 Chimeric Heavy Chain CDR₃ 33 Sh4F11 Hv3-23 Heavy Chain Variable Region-nucleic acid 34 Sh4F11 Hv3-23 Heavy Chain Variable Region-protein 5 Sh4F11 Hv3-23 Heavy Chain CDR₁ 6 Sh4F11 Hv3-23 Heavy Chain CDR₂ 7 Sh4F11 Hv3-23 Heavy Chain CDR₃ 35 Sh4F11 Hv3-23 A28T S31H T62S Heavy Chain Variable Region-nucleic acid 36 Sh4F11 Hv3-23 A28T S31H T62S Heavy Chain Variable Region-protein 51 Sh4F11 Hv3-23 A28T S31H T62S Heavy Chain CDR1 53 Sh4F11 Hv3-23 A28T S31H T62S Heavy Chain CDR₂ 7 Sh4F11 Hv3-23 A28T S31H T62S Heavy Chain CDR₃ 37 Sh4F11 Hv3-23 S31H T62S Heavy Chain Variable Region- nucleic acid 38 Sh4F11 Hv3-23 S31H T62S Heavy Chain Variable Region- protein 51 Sh4F11 Hv3-23 S31H T62S Heavy Chain CDR₁ 53 Sh4F11 Hv3-23 S31H T62S Heavy Chain CDR₂ 7 Sh4F11 Hv3-23 S31H T62S Heavy Chain CDR₃ 39 Sh4F11 Hv3-23 A28T S31N T62S Heavy Chain Variable Region-nucleic acid 40 Sh4F11 Hv3-23 A28T S31N T62S Heavy Chain Variable Region-protein 52 Sh4F11 Hv3-23 A28T S31N T62S Heavy Chain CDR₁ 53 Sh4F11 Hv3-23 A28T S31N T62S Heavy Chain CDR₂ 7 Sh4F11 Hv3-23 A28T S31N T62S Heavy Chain CDR₃ 41 Sh4F11 Hv3-23 A28T T62S Heavy Chain Variable Region- nucleic acid 42 Sh4F11 Hv3-23 A28T T62S Heavy Chain Variable Region- protein 5 Sh4F11 Hv3-23 A28T T62S Heavy Chain CDR₁ 53 Sh4F11 Hv3-23 A28T T62S Heavy Chain CDR₂ 7 Sh4F11 Hv3-23 A28T T62S Heavy Chain CDR₃ 32 Ch4F11 Chimeric Light (kappa) Chain Variable Region- nucleic acid 4 Ch4F11 Chimeric Light (kappa) Chain Variable Region- protein 8 Ch4F11 Chimeric Light (kappa) Chain CDR₁ 9 Ch4F11 Chimeric Light (kappa) Chain CDR₂ 10 Ch4F11 Chimeric Light (kappa) Chain CDR₃ 43 Hu4F11 Kv2D-29 Light (kappa) Chain Variable Region- nucleic acid 44 Hu4F11 Kv2D-29 Light (kappa) Chain Variable Region- protein 8 Hu4F11 Kv2D-29 Light (kappa) Chain CDR₁ 9 Hu4F11 Kv2D-29 Light (kappa) Chain CDR₂ 10 Hu4F11 Kv2D-29 Light (kappa) Chain CDR₃ 45 Hu4F11 Kv2D-29 N28H Light (kappa) Chain Variable Region-nucleic acid 46 Hu4F11 Kv2D-29 N28H Light (kappa) Chain Variable Region-protein 62 Hu4F11 Kv2D-29 N28H Light (kappa) Chain CDR₁ 9 Hu4F11 Kv2D-29 N28H Light (kappa) Chain CDR₂ 10 Hu4F11 Kv2D-29 N28H Light (kappa) Chain CDR₃ 47 Hu4F11 Kv2D-29 N28Q Light (kappa) Chain Variable Region-nucleic acid 48 Hu4F11 Kv2D-29 N28Q Light (kappa) Chain Variable Region-protein 63 Hu4F11 Kv2D-29 N28Q Light (kappa) Chain CDR₁ 9 Hu4F11 Kv2D-29 N28Q Light (kappa) Chain CDR₂ 10 Hu4F11 Kv2D-29 N28Q Light (kappa) Chain CDR₃ 49 Hu4F11 Kv2D-29 N28Y Light (kappa) Chain Variable Region-nucleic acid 50 Hu4F11 Kv2D-29 N28Y Light (kappa) Chain Variable Region-protein 64 Hu4F11 Kv2D-29 N28Y Light (kappa) Chain CDR₁ 9 Hu4F11 Kv2D-29 N28Y Light (kappa) Chain CDR₂ 10 Hu4F11 Kv2D-29 N28Y Light (kappa) Chain CDR₃

Humanized monoclonal antibody heavy chain CDR sequences (Kabat, Chothia, and IMGT definitions) are shown in Table 10.

TABLE 10 Variable Region SEQ ID CDR1 CRD2 CDR3 NO: Kabat Ch4F11 SYDMS YISRGGGSTYYPDTVKG HATTAYWYFDV 2 Chimeric (SEQ ID NO: 5) (SEQ ID NO: 6) (SEQ ID NO: 7) Sh4F11 Hv3- SYDMS YISRGGGSTYYPDTVKG HATTAYWYFDV 34 23 (SEQ ID NO: 5) (SEQ ID NO: 6) (SEQ ID NO: 7) Sh4F11 Hv3- HYDMS YISRGGGSTYYPDSVKG HATTAYWYFDV 36 23 A28T (SEQ ID NO: 51) (SEQ ID NO: 53) (SEQ ID NO: 7) S31H T62S Sh4F11 Hv3- HYDMS YISRGGGSTYYPDSVKG HATTAYWYFDV 38 23 S31H (SEQ ID NO: 51) (SEQ ID NO: 53) (SEQ ID NO: 7) T62S Sh4F11 Hv3- NYDMS YISRGGGSTYYPDSVKG HATTAYWYFDV 40 23 A28T (SEQ ID NO: 52) (SEQ ID NO: 53) (SEQ ID NO: 7) S31N T62S Sh4F11 Hv3- SYDMS YISRGGGSTYYPDSVKG HATTAYWYFDV 42 23 A28T (SEQ ID NO: 5) (SEQ ID NO: 53) (SEQ ID NO: 7) T62S Chothia Ch4F11 GFAFSSY SRGGGS HATTAYWYFDV 2 Chimeric (SEQ ID NO: 11) (SEQ ID NO: 12) (SEQ ID NO: 7) Sh4F11 Hv3- GFAFSSY SRGGGS HATTAYWYFDV 34 23 (SEQ ID NO: 11) (SEQ ID NO: 12) (SEQ ID NO: 7) Sh4F11 Hv3- GFTFSHY SRGGGS HATTAYWYFDV 36 23 A28T (SEQ ID NO: 54) (SEQ ID NO: 12) (SEQ ID NO: 7) S31H T62S Sh4F11 Hv3- GFAFSHY SRGGGS HATTAYWYFDV 38 23 S31H (SEQ ID NO: 55) (SEQ ID NO: 12) (SEQ ID NO: 7) T62S Sh4F11 Hv3- GFTFSNY SRGGGS HATTAYWYFDV 40 23 A28T (SEQ ID NO: 56) (SEQ ID NO: 12) (SEQ ID NO: 7) S31N T62S Sh4F11 Hv3- GFTFSNY SRGGGS HATTAYWYFDV 42 23 A28T (SEQ ID NO: 57) (SEQ ID NO: 12) (SEQ ID NO: 7) T62S IMGT Ch4F11 GFAFSSYD ISRGGGST GRHATTAYWYFDV 2 Chimeric (SEQ ID NO: 14) (SEQ ID NO: 15) (SEQ ID NO: 16) Sh4F11 Hv3- GFAFSSYD ISRGGGST GRHATTAYWYFDV 34 23 (SEQ ID NO: 14) (SEQ ID NO: 15) (SEQ ID NO: 16) Sh4F11 Hv3- GFTFSHYD ISRGGGST GRHATTAYWYFDV 36 23 A28T (SEQ ID NO: 58) (SEQ ID NO: 15) (SEQ ID NO: 16) S31H T62S Sh4F11 Hv3- GFAFSHYD ISRGGGST GRHATTAYWYFDV 38 23 S31H (SEQ ID NO: 59) (SEQ ID NO: 15) (SEQ ID NO: 16) T62S Sh4F11 Hv3- GFTFSNYD ISRGGGST GRHATTAYWYFDV 40 23 A28T (SEQ ID NO: 60) (SEQ ID NO: 15) (SEQ ID NO: 16) S31N T62S Sh4F11 Hv3- GFTFSSYD ISRGGGST GRHATTAYWYFDV 42 23 A28T (SEQ ID NO: 61) (SEQ ID NO: 15) (SEQ ID NO: 16) T62S

Humanized monoclonal antibody Kappa light chain CDR sequences (Kabat, Chothia, and IMGT definitions) are shown in Table 11.

TABLE 11 Variable Region SEQ CDR1 CRD2 CDR3 ID NO: Kabat/Chothia Ch4F11 RSSQSLVHTNGNTYLH KVSNRFS SQSTHVPWT 4 Chimeric (SEQ ID NO: 8) (SEQ ID NO: 9) (SEQ ID NO: 10) Hu4F11 RSSQSLVHTNGNTYLH KVSNRFS SQSTHVPWT 44 Kv2D-29 (SEQ ID NO: 8) (SEQ ID NO: 9) (SEQ ID NO: 10) Hu4F11 RSSQSLVHTHGNTYLH KVSNRFS SQSTHVPWT 46 Kv2D-29 (SEQ ID NO: 62) (SEQ ID NO: 9) (SEQ ID NO: 10) N28H Hu4F11 RSSQSLVHTQGNTYLH KVSNRFS SQSTHVPWT 48 Kv2D-29 (SEQ ID NO: 63) (SEQ ID NO: 9) (SEQ ID NO: 10) N28Q Hu4F11 RSSQSLVHTYGNTYLH KVSNRFS SQSTHVPWT 50 Kv2D-29 (SEQ ID NO: 64) (SEQ ID NO: 9) (SEQ ID NO: 10) N28Y IMGT Ch4F11 QSLVHTNGNTY KVS SQSTHVPWT 4 Chimeric (SEQ ID NO: 20) (SEQ ID NO: 10) Hu4F11 QSLVHTNGNTY KVS SQSTHVPWT 44 Kv2D-29 (SEQ ID NO: 20) (SEQ ID NO: 10) Hu4F11 QSLVHTHGNTY KVS SQSTHVPWT 46 Kv2D-29 (SEQ ID NO: 65) (SEQ ID NO: 10) N28H Hu4F11 QSLVHTQGNTY KVS SQSTHVPWT 48 Kv2D-29 (SEQ ID NO: 66) (SEQ ID NO: 10) N28Q Hu4F11 QSLVHTYGNTY KVS SQSTHVPWT 50 Kv2D-29 (SEQ ID NO: 67) (SEQ ID NO: 10) N28Y

To create the complete chimeric and humanized heavy or kappa chain antibody sequences, each variable sequence above is combined with its respective human constant region. For example, a complete heavy chain comprises a heavy variable sequence followed by a human IgG1 heavy chain constant sequence. A complete kappa chain comprises a kappa variable sequence followed by the human kappa light chain constant sequence.

Nucleic Acid Sequence Encoding the Human IgG1 Heavy Chain Constant Region (SEQ ID NO:68)

1 gcctcaacaa aaggaccaag tgtgttccca ctcgccccta gcagcaagag tacatccggg 61 ggcactgcag cactcggctg cctcgtcaag gattattttc cagagccagt aaccgtgagc 121 tggaacagtg gagcactcac ttctggtgtc catacttttc ctgctgtcct gcaaagctct 181 ggcctgtact cactcagctc cgtcgtgacc gtgccatctt catctctggg cactcagacc 241 tacatctgta atgtaaacca caagcctagc aatactaagg tcgataagcg ggtggaaccc 301 aagagctgcg acaagactca cacttgtccc ccatgccctg cccctgaact tctgggcggt 361 cccagcgtct ttttgttccc accaaagcct aaagatactc tgatgataag tagaacaccc 421 gaggtgacat gtgttgttgt agacgtttcc cacgaggacc cagaggttaa gttcaactgg 481 tacgttgatg gagtcgaagt acataatgct aagaccaagc ctagagagga gcagtataat 541 agtacatacc gtgtagtcag tgttctcaca gtgctgcacc aagactggct caacggcaaa 601 gaatacaaat gcaaagtgtc caacaaagca ctcccagccc ctatcgagaa gactattagt 661 aaggcaaagg ggcagcctcg tgaaccacag gtgtacactc tgccacccag tagagaggaa 721 atgacaaaga accaagtctc attgacctgc ctggtgaaag gcttctaccc cagcgacatc 781 gccgttgagt gggagagtaa cggtcagcct gagaacaatt acaagacaac ccccccagtg 841 ctggatagtg acgggtcttt ctttctgtac agtaagctga ctgtggacaa gtcccgctgg 901 cagcagggta acgtcttcag ctgttccgtg atgcacgagg cattgcacaa ccactacacc 961 cagaagtcac tgagcctgag cccagggaag

Protein Sequence Defining the Human IgG1 Heavy Chain Constant Region (SEQ ID NO:69)

1 astkgpsvfp lapsskstsg gtaalgclvk dyfpepvtvs wnsgaltsgv htfpavlqss 61 glyslssvvt vpssslgtqt yicnvnhkps ntkvdkrvep kscdkthtcp pcpapellgg 121 psvflfppkp kdtlmisrtp evtcvvvdvs hedpevkfnw yvdgvevhna ktkpreeqyn 181 styrvvsvlt vlhqdwlngk eykckvsnka lpapiektis kakgqprepq vytlppsree 241 mtknqvsltc lvkgfypsdi avewesngqp ennykttppv ldsdgsffly skltvdksrw 301 qqgnvfscsv mhealhnhyt qkslslspgk

Nucleic Acid Sequence Encoding the Human Kappa Light Chain Constant Region (Version 1) (SEQ ID NO:70)

1 cgcacagttg ctgcccccag cgtgttcatt ttcccaccta gcgatgagca gctgaaaagc 61 ggtactgcct ctgtcgtatg cttgctcaac aacttttacc cacgtgaggc taaggtgcag 121 tggaaagtgg ataatgcact tcaatctgga aacagtcaag agtccgtgac agaacaggac 181 agcaaagact caacttattc actctcttcc accctgactc tgtccaaggc agactatgaa 241 aaacacaagg tatacgcctg cgaggttaca caccagggtt tgtctagtcc tgtcaccaag 301 tccttcaata ggggcgaatg t

Nucleic Acid Sequence Encoding the Human Kappa Light Chain Constant Region (Version 2) (SEQ ID NO:71)

1 cgcacagttg cagcccccag cgtgttcatt ttcccaccta gcgatgagca gctgaaaagc 61 ggtactgcct ctgtcgtatg cttgctcaac aacttttacc cacgtgaggc taaggtgcag 121 tggaaagtgg ataatgcact tcaatctgga aacagtcaag agtccgtgac agaacaggac 181 agcaaagact caacttattc actctcttcc accctgactc tgtccaaggc agactatgaa 241 aaacacaagg tatacgcctg cgaggttaca caccagggtt tgtctagtcc tgtcaccaag 301 tccttcaata ggggcgaatg t

Protein Sequence Defining the Human Kappa Light Chain Constant Region (nucleic Acid Versions 1 and 2 Encode the Same Amino Acid Sequence) (SEQ ID NO:72)

1 rtvaapsvfi fppsdeqlks gtasvvclln nfypreakvq wkvdnalqsg nsqesvteqd 61 skdstyslss tltlskadye khkvyacevt hqglsspvtk sfnrgec

The following sequences represent the actual or contemplated full length heavy and light chain sequence (i.e., containing both the variable and constant regions sequences) for each antibody described in this Example. Signal sequences for proper secretion of the antibodies (e.g., signal sequences at the 5′ end of the DNA sequences or the amino terminal end of the protein sequences) are not shown in the full length heavy and light chain sequences disclosed herein and are not included in the final secreted protein. Also not shown are stop codons for termination of translation required at the 3′ end of the DNA sequences. It is within ordinary skill in the art to select a signal sequence and/or a stop codon for expression of the disclosed full length immunoglobulin heavy chain and light chain sequences. It is also contemplated that the variable region sequences can be ligated to other constant region sequences to produce active full length immunoglobulin heavy and light chains.

Nucleic Acid Sequence Encoding the Full Length Ch4F11 Chimeric Heavy Chain (Mouse Heavy Chain Variable Region and Human IgG1 Constant Region) (SEQ ID NO:73)

1 gaggtacagc ttgtcgagtc gggaggagga ttggtaaaac cgggtgggtc actcaaattg 61 tcgtgtgcgg cgtcgggatt tgcgttttcg tcgtatgata tgtcgtgggt gcgccagacg 121 ccggaaaaac gattggaatg ggtcgcgtat atctcccgag ggggaggttc gacatactat 181 cccgacacgg tcaaagggcg cttcacgatt tcacgggaca atgcgaaaaa cacgctttat 241 cttcaaatgt cgtcgttgaa atcggaagat accgcgatgt attactgcgg gaggcatgcg 301 acgacggcgt attggtattt cgatgtgtgg ggagccggaa cgacggtgac ggtgtcgtcg 361 gcctcaacaa aaggaccaag tgtgttccca ctcgccccta gcagcaagag tacatccggg 421 ggcactgcag cactcggctg cctcgtcaag gattattttc cagagccagt aaccgtgagc 481 tggaacagtg gagcactcac ttctggtgtc catacttttc ctgctgtcct gcaaagctct 541 ggcctgtact cactcagctc cgtcgtgacc gtgccatctt catctctggg cactcagacc 601 tacatctgta atgtaaacca caagcctagc aatactaagg tcgataagcg ggtggaaccc 661 aagagctgcg acaagactca cacttgtccc ccatgccctg cccctgaact tctgggcggt 721 cccagcgtct ttttgttccc accaaagcct aaagatactc tgatgataag tagaacaccc 781 gaggtgacat gtgttgttgt agacgtttcc cacgaggacc cagaggttaa gttcaactgg 841 tacgttgatg gagtcgaagt acataatgct aagaccaagc ctagagagga gcagtataat 901 agtacatacc gtgtagtcag tgttctcaca gtgctgcacc aagactggct caacggcaaa 961 gaatacaaat gcaaagtgtc caacaaagca ctcccagccc ctatcgagaa gactattagt 1021 aaggcaaagg ggcagcctcg tgaaccacag gtgtacactc tgccacccag tagagaggaa 1081 atgacaaaga accaagtctc attgacctgc ctggtgaaag gcttctaccc cagcgacatc 1141 gccgttgagt gggagagtaa cggtcagcct gagaacaatt acaagacaac ccccccagtg 1201 ctggatagtg acgggtcttt ctttctgtac agtaagctga ctgtggacaa gtcccgctgg 1261 cagcagggta acgtcttcag ctgttccgtg atgcacgagg cattgcacaa ccactacacc 1321 cagaagtcac tgagcctgag cccagggaag

Protein Sequence Defining the Full Length Ch4F11 Chimeric Heavy Chain (Mouse Heavy Chain Variable Region and Human IgG1 Constant Region) (SEQ ID NO:74)

1 evqlvesggg lvkpggslkl scaasgfafs sydmswvrqt pekrlewvay isrgggstyy 61 pdtvkgrfti srdnakntly lqmsslksed tamyycgrha ttaywyfdvw gagttvtvss 121 astkgpsvfp lapsskstsg gtaalgclvk dyfpepvtvs wnsgaltsgv htfpavlqss 181 glyslssvvt vpssslgtqt yicnvnhkps ntkvdkrvep kscdkthtcp pcpapellgg 241 psvflfppkp kdtlmisrtp evtcvvvdvs hedpevkfnw yvdgvevhna ktkpreeqyn 301 styrvvsvlt vlhqdwlngk eykckvsnka lpapiektis kakgqprepq vytlppsree 361 mtknqvsltc lvkgfypsdi avewesngqp ennykttppv ldsdgsffly skltvdksrw 421 qqgnvfscsv mhealhnhyt qkslslspgk

Nucleic Acid Sequence Encoding the Full Length Sh4F11 Hv3-23 Heavy Chain (Humanized Heavy Chain Variable Region and Human IgG1 Constant Region) (SEQ ID NO:75)

1 gaagtacagt tgttggagtc aggaggaggg ttggtccagc cgggtggatc gttgcggctt 61 tcgtgtgcgg cgtcgggatt cgcgttttca tcgtatgaca tgtcgtgggt gaggcaggca 121 ccggggaaag ggcttgaatg ggtatcgtac atttcgagag ggggaggatc gacgtattac 181 ccggatacgg tgaaaggaag gtttacgatc tcgcgcgaca attcaaagaa tacgctttat 241 cttcagatga actcgctccg agcggaagat acggcggtat actattgcgg tcgccatgcg 301 acgacggcgt attggtattt cgatgtgtgg ggacaaggga cgatggtcac ggtgtcgtcg 361 gcctcaacaa aaggaccaag tgtgttccca ctcgccccta gcagcaagag tacatccggg 421 ggcactgcag cactcggctg cctcgtcaag gattattttc cagagccagt aaccgtgagc 481 tggaacagtg gagcactcac ttctggtgtc catacttttc ctgctgtcct gcaaagctct 541 ggcctgtact cactcagctc cgtcgtgacc gtgccatctt catctctggg cactcagacc 601 tacatctgta atgtaaacca caagcctagc aatactaagg tcgataagcg ggtggaaccc 661 aagagctgcg acaagactca cacttgtccc ccatgccctg cccctgaact tctgggcggt 721 cccagcgtct ttttgttccc accaaagcct aaagatactc tgatgataag tagaacaccc 781 gaggtgacat gtgttgttgt agacgtttcc cacgaggacc cagaggttaa gttcaactgg 841 tacgttgatg gagtcgaagt acataatgct aagaccaagc ctagagagga gcagtataat 901 agtacatacc gtgtagtcag tgttctcaca gtgctgcacc aagactggct caacggcaaa 961 gaatacaaat gcaaagtgtc caacaaagca ctcccagccc ctatcgagaa gactattagt 1021 aaggcaaagg ggcagcctcg tgaaccacag gtgtacactc tgccacccag tagagaggaa 1081 atgacaaaga accaagtctc attgacctgc ctggtgaaag gcttctaccc cagcgacatc 1141 gccgttgagt gggagagtaa cggtcagcct gagaacaatt acaagacaac ccccccagtg 1201 ctggatagtg acgggtcttt ctttctgtac agtaagctga ctgtggacaa gtcccgctgg 1261 cagcagggta acgtcttcag ctgttccgtg atgcacgagg cattgcacaa ccactacacc 1321 cagaagtcac tgagcctgag cccagggaag

Protein Sequence Defining the Full Length Sh4F11 Hv3-23 Heavy Chain (Humanized Heavy Chain Variable Region and Human IgG1 Constant Region) (SEQ ID NO:76)

1 evqllesggg lvqpggslrl scaasgfafs sydmswvrqa pgkglewvsy isrgggstyy 61 pdtvkgrfti srdnskntly lqmnslraed tavyycgrha ttaywyfdvw gqgtmvtvss 121 astkgpsvfp lapsskstsg gtaalgclvk dyfpepvtvs wnsgaltsgv htfpavlqss 181 glyslssvvt vpssslgtqt yicnvnhkps ntkvdkrvep kscdkthtcp pcpapellgg 241 psvflfppkp kdtlmisrtp evtcvvvdvs hedpevkfnw yvdgvevhna ktkpreeqyn 301 styrvvsvlt vlhqdwlngk eykckvsnka lpapiektis kakgqprepq vytlppsree 361 mtknqvsltc lvkgfypsdi avewesngqp ennykttppv ldsdgsffly skltvdksrw 421 qqgnvfscsv mhealhnhyt qkslslspgk

Nucleic Acid Sequence Encoding the Full Length Sh4F11 Hv3-23 A28T S31H T62S Heavy Chain (Humanized Heavy Chain Variable Region and Human IgG1 Constant Region) (SEQ ID NO:77)

1 gaagtacagt tgttggagtc aggaggaggg ttggtccagc cgggtggatc gttgcggctt 61 tcgtgtgcgg cgtcgggatt caccttttca cactatgaca tgtcgtgggt gaggcaggca 121 ccggggaaag ggcttgaatg ggtatcgtac atttcgagag ggggaggatc gacgtattac 181 ccggattccg tgaaaggaag gtttacgatc tcgcgcgaca attcaaagaa tacgctttat 241 cttcagatga actcgctccg agcggaagat acggcggtat actattgcgg tcgccatgcg 301 acgacggcgt attggtattt cgatgtgtgg ggacaaggga cgatggtcac ggtgtcgtcg 361 gcctcaacaa aaggaccaag tgtgttccca ctcgccccta gcagcaagag tacatccggg 421 ggcactgcag cactcggctg cctcgtcaag gattattttc cagagccagt aaccgtgagc 481 tggaacagtg gagcactcac ttctggtgtc catacttttc ctgctgtcct gcaaagctct 541 ggcctgtact cactcagctc cgtcgtgacc gtgccatctt catctctggg cactcagacc 601 tacatctgta atgtaaacca caagcctagc aatactaagg tcgataagcg ggtggaaccc 661 aagagctgcg acaagactca cacttgtccc ccatgccctg cccctgaact tctgggcggt 721 cccagcgtct ttttgttccc accaaagcct aaagatactc tgatgataag tagaacaccc 781 gaggtgacat gtgttgttgt agacgtttcc cacgaggacc cagaggttaa gttcaactgg 841 tacgttgatg gagtcgaagt acataatgct aagaccaagc ctagagagga gcagtataat 901 agtacatacc gtgtagtcag tgttctcaca gtgctgcacc aagactggct caacggcaaa 961 gaatacaaat gcaaagtgtc caacaaagca ctcccagccc ctatcgagaa gactattagt 1021 aaggcaaagg ggcagcctcg tgaaccacag gtgtacactc tgccacccag tagagaggaa 1081 atgacaaaga accaagtctc attgacctgc ctggtgaaag gcttctaccc cagcgacatc 1141 gccgttgagt gggagagtaa cggtcagcct gagaacaatt acaagacaac ccccccagtg 1201 ctggatagtg acgggtcttt ctttctgtac agtaagctga ctgtggacaa gtcccgctgg 1261 cagcagggta acgtcttcag ctgttccgtg atgcacgagg cattgcacaa ccactacacc 1321 cagaagtcac tgagcctgag cccagggaag

Protein Sequence Defining the Full Length Sh4F11 Hv3-23 A28T S31H T62S Heavy Chain (Humanized Heavy Chain Variable Region and Human IgG1 Constant Region) (SEQ ID NO:78)

1 evqllesggg lvqpggslrl scaasgftfs hydmswvrqa pgkglewvsy isrgggstyy 61 pdsvkgrfti srdnskntly lqmnslraed tavyycgrha ttaywyfdvw gqgtmvtvss 121 astkgpsvfp lapsskstsg gtaalgclvk dyfpepvtvs wnsgaltsgv htfpavlqss 181 glyslssvvt vpssslgtqt yicnvnhkps ntkvdkrvep kscdkthtcp pcpapellgg 241 psvflfppkp kdtlmisrtp evtcvvvdvs hedpevkfnw yvdgvevhna ktkpreeqyn 301 styrvvsvlt vlhqdwlngk eykckvsnka lpapiektis kakgqprepq vytlppsree 361 mtknqvsltc lvkgfypsdi avewesngqp ennykttppv ldsdgsffly skltvdksrw 421 qqgnvfscsv mhealhnhyt qkslslspgk

Nucleic Acid Sequence Encoding the Full Length Sh4F11 Hv3-23 S31H T62S Heavy Chain (Humanized Heavy Chain Variable Region and Human IgG1 Constant Region) (SEQ ID NO:79)

1 gaagtacagt tgttggagtc aggaggaggg ttggtccagc cgggtggatc gttgcggctt 61 tcgtgtgcgg cgtcgggatt cgcgttttca cactatgaca tgtcgtgggt gaggcaggca 121 ccggggaaag ggcttgaatg ggtatcgtac atttcgagag ggggaggatc gacgtattac 181 ccggattccg tgaaaggaag gtttacgatc tcgcgcgaca attcaaagaa tacgctttat 241 cttcagatga actcgctccg agcggaagat acggcggtat actattgcgg tcgccatgcg 301 acgacggcgt attggtattt cgatgtgtgg ggacaaggga cgatggtcac ggtgtcgtcg 361 gcctcaacaa aaggaccaag tgtgttccca ctcgccccta gcagcaagag tacatccggg 421 ggcactgcag cactcggctg cctcgtcaag gattattttc cagagccagt aaccgtgagc 481 tggaacagtg gagcactcac ttctggtgtc catacttttc ctgctgtcct gcaaagctct 541 ggcctgtact cactcagctc cgtcgtgacc gtgccatctt catctctggg cactcagacc 601 tacatctgta atgtaaacca caagcctagc aatactaagg tcgataagcg ggtggaaccc 661 aagagctgcg acaagactca cacttgtccc ccatgccctg cccctgaact tctgggcggt 721 cccagcgtct ttttgttccc accaaagcct aaagatactc tgatgataag tagaacaccc 781 gaggtgacat gtgttgttgt agacgtttcc cacgaggacc cagaggttaa gttcaactgg 841 tacgttgatg gagtcgaagt acataatgct aagaccaagc ctagagagga gcagtataat 901 agtacatacc gtgtagtcag tgttctcaca gtgctgcacc aagactggct caacggcaaa 961 gaatacaaat gcaaagtgtc caacaaagca ctcccagccc ctatcgagaa gactattagt 1021 aaggcaaagg ggcagcctcg tgaaccacag gtgtacactc tgccacccag tagagaggaa 1081 atgacaaaga accaagtctc attgacctgc ctggtgaaag gcttctaccc cagcgacatc 1141 gccgttgagt gggagagtaa cggtcagcct gagaacaatt acaagacaac ccccccagtg 1201 ctggatagtg acgggtcttt ctttctgtac agtaagctga ctgtggacaa gtcccgctgg 1261 cagcagggta acgtcttcag ctgttccgtg atgcacgagg cattgcacaa ccactacacc 1321 cagaagtcac tgagcctgag cccagggaag

Protein Sequence Defining the Full Length Sh4F11 Hv3-23 S31H T62S Heavy Chain (Humanized Heavy Chain Variable Region and Human IgG1 Constant Region) (SEQ ID NO:80)

1 evqllesggg lvqpggslrl scaasgfafs hydmswvrqa pgkglewvsy isrgggstyy 61 pdsvkgrfti srdnskntly lqmnslraed tavyycgrha ttaywyfdvw gqgtmvtvss 121 astkgpsvfp lapsskstsg gtaalgclvk dyfpepvtvs wnsgaltsgv htfpavlqss 181 glyslssvvt vpssslgtqt yicnvnhkps ntkvdkrvep kscdkthtcp pcpapellgg 241 psvflfppkp kdtlmisrtp evtcvvvdvs hedpevkfnw yvdgvevhna ktkpreeqyn 301 styrvvsvlt vlhqdwlngk eykckvsnka lpapiektis kakgqprepq vytlppsree 361 mtknqvsltc lvkgfypsdi avewesngqp ennykttppv ldsdgsffly skltvdksrw 421 qqgnvfscsv mhealhnhyt qkslslspgk

Nucleic Acid Sequence Encoding the Full Length Sh4F11 Hv3-23 A28T S31N T62S Heavy Chain (Humanized Heavy Chain Variable Region and Human IgG1 Constant Region) (SEQ ID NO:81)

1 gaagtacagt tgttggagtc aggaggaggg ttggtccagc cgggtggatc gttgcggctt 61 tcgtgtgcgg cgtcgggatt caccttttca aactatgaca tgtcgtgggt gaggcaggca 121 ccggggaaag ggcttgaatg ggtatcgtac atttcgagag ggggaggatc gacgtattac 181 ccggattccg tgaaaggaag gtttacgatc tcgcgcgaca attcaaagaa tacgctttat 241 cttcagatga actcgctccg agcggaagat acggcggtat actattgcgg tcgccatgcg 301 acgacggcgt attggtattt cgatgtgtgg ggacaaggga cgatggtcac ggtgtcgtcg 361 gcctcaacaa aaggaccaag tgtgttccca ctcgccccta gcagcaagag tacatccggg 421 ggcactgcag cactcggctg cctcgtcaag gattattttc cagagccagt aaccgtgagc 481 tggaacagtg gagcactcac ttctggtgtc catacttttc ctgctgtcct gcaaagctct 541 ggcctgtact cactcagctc cgtcgtgacc gtgccatctt catctctggg cactcagacc 601 tacatctgta atgtaaacca caagcctagc aatactaagg tcgataagcg ggtggaaccc 661 aagagctgcg acaagactca cacttgtccc ccatgccctg cccctgaact tctgggcggt 721 cccagcgtct ttttgttccc accaaagcct aaagatactc tgatgataag tagaacaccc 781 gaggtgacat gtgttgttgt agacgtttcc cacgaggacc cagaggttaa gttcaactgg 841 tacgttgatg gagtcgaagt acataatgct aagaccaagc ctagagagga gcagtataat 901 agtacatacc gtgtagtcag tgttctcaca gtgctgcacc aagactggct caacggcaaa 961 gaatacaaat gcaaagtgtc caacaaagca ctcccagccc ctatcgagaa gactattagt 1021 aaggcaaagg ggcagcctcg tgaaccacag gtgtacactc tgccacccag tagagaggaa 1081 atgacaaaga accaagtctc attgacctgc ctggtgaaag gcttctaccc cagcgacatc 1141 gccgttgagt gggagagtaa cggtcagcct gagaacaatt acaagacaac ccccccagtg 1201 ctggatagtg acgggtcttt ctttctgtac agtaagctga ctgtggacaa gtcccgctgg 1261 cagcagggta acgtcttcag ctgttccgtg atgcacgagg cattgcacaa ccactacacc 1321 cagaagtcac tgagcctgag cccagggaag

Protein Sequence Defining the Full Length Sh4F11 A28T S31N T62S Heavy Chain (Humanized Heavy Chain Variable Region and Human IgG1 Constant Region) (SEQ ID NO:82)

1 evqllesggg lvqpggslrl scaasgftfs nydmswvrqa pgkglewvsy isrgggstyy 61 pdsvkgrfti srdnskntly lqmnslraed tavyycgrha ttaywyfdvw gqgtmvtvss 121 astkgpsvfp lapsskstsg gtaalgclvk dyfpepvtvs wnsgaltsgv htfpavlqss 181 glyslssvvt vpssslgtqt yicnvnhkps ntkvdkrvep kscdkthtcp pcpapellgg 241 psvflfppkp kdtlmisrtp evtcvvvdvs hedpevkfnw yvdgvevhna ktkpreeqyn 301 styrvvsvlt vlhqdwlngk eykckvsnka lpapiektis kakgqprepq vytlppsree 361 mtknqvsltc lvkgfypsdi avewesngqp ennykttppv ldsdgsffly skltvdksrw 421 qqgnvfscsv mhealhnhyt qkslslspgk

Nucleic Acid Sequence Encoding the Full Length Sh4F11 Hv3-23 A28T T62S Heavy Chain (Humanized Heavy Chain Variable Region and Human IgG1 Constant Region) (SEQ ID NO:83)

1 gaagtacagt tgttggagtc aggaggaggg ttggtccagc cgggtggatc gttgcggctt 61 tcgtgtgcgg cgtcgggatt caccttttca tcgtatgaca tgtcgtgggt gaggcaggca 121 ccggggaaag ggcttgaatg ggtatcgtac atttcgagag ggggaggatc gacgtattac 181 ccggattccg tgaaaggaag gtttacgatc tcgcgcgaca attcaaagaa tacgctttat 241 cttcagatga actcgctccg agcggaagat acggcggtat actattgcgg tcgccatgcg 301 acgacggcgt attggtattt cgatgtgtgg ggacaaggga cgatggtcac ggtgtcgtcg 361 gcctcaacaa aaggaccaag tgtgttccca ctcgccccta gcagcaagag tacatccggg 421 ggcactgcag cactcggctg cctcgtcaag gattattttc cagagccagt aaccgtgagc 481 tggaacagtg gagcactcac ttctggtgtc catacttttc ctgctgtcct gcaaagctct 541 ggcctgtact cactcagctc cgtcgtgacc gtgccatctt catctctggg cactcagacc 601 tacatctgta atgtaaacca caagcctagc aatactaagg tcgataagcg ggtggaaccc 661 aagagctgcg acaagactca cacttgtccc ccatgccctg cccctgaact tctgggcggt 721 cccagcgtct ttttgttccc accaaagcct aaagatactc tgatgataag tagaacaccc 781 gaggtgacat gtgttgttgt agacgtttcc cacgaggacc cagaggttaa gttcaactgg 841 tacgttgatg gagtcgaagt acataatgct aagaccaagc ctagagagga gcagtataat 901 agtacatacc gtgtagtcag tgttctcaca gtgctgcacc aagactggct caacggcaaa 961 gaatacaaat gcaaagtgtc caacaaagca ctcccagccc ctatcgagaa gactattagt 1021 aaggcaaagg ggcagcctcg tgaaccacag gtgtacactc tgccacccag tagagaggaa 1081 atgacaaaga accaagtctc attgacctgc ctggtgaaag gcttctaccc cagcgacatc 1141 gccgttgagt gggagagtaa cggtcagcct gagaacaatt acaagacaac ccccccagtg 1201 ctggatagtg acgggtcttt ctttctgtac agtaagctga ctgtggacaa gtcccgctgg 1261 cagcagggta acgtcttcag ctgttccgtg atgcacgagg cattgcacaa ccactacacc 1321 cagaagtcac tgagcctgag cccagggaag

Protein Sequence Defining the Full Length Sh4F11 Hv3-23 A28T T62SHeavy Chain (Humanized Heavy Chain Variable Region and Human IgG1 Constant Region) (SEQ ID NO:84)

1 evqllesggg lvqpggslrl scaasgftfs sydmswvrqa pgkglewvsy isrgggstyy 61 pdsvkgrfti srdnskntly lqmnslraed tavyycgrha ttaywyfdvw gqgtmvtvss 121 astkgpsvfp lapsskstsg gtaalgclvk dyfpepvtvs wnsgaltsgv htfpavlqss 181 glyslssvvt vpssslgtqt yicnvnhkps ntkvdkrvep kscdkthtcp pcpapellgg 241 psvflfppkp kdtlmisrtp evtcvvvdvs hedpevkfnw yvdgvevhna ktkpreeqyn 301 styrvvsvlt vlhqdwlngk eykckvsnka lpapiektis kakgqprepq vytlppsree 361 mtknqvsltc lvkgfypsdi avewesngqp ennykttppv ldsdgsffly skltvdksrw 421 qqgnvfscsv mhealhnhyt qkslslspgk

Nucleic Acid Sequence Encoding the Full Length Ch4F11 Chimeric Light Chain (Mouse Kappa Chain Variable Region and Human Kappa Constant Region) (SEQ ID NO:85)

1 gacgtggtaa tgacgcagac gccgttgtcc cttcctgtct cgctcggaga tcaggcgtcg 61 atctcgtgta gaagctcgca gtcactcgtc cataccaacg ggaatacata tcttcactgg 121 tatttgcaaa agcccggaca gtcaccgaag ctcttgatct acaaagtatc caatcggttt 181 tcgggggtgc ccgaccgatt ctcgggatcg ggttcgggga cggattttac gttgaagatt 241 tcgcgggtgg aagcggagga tctcggtgtc tacttttgtt cgcagtcaac gcatgtcccg 301 tggacgttcg gaggcgggac aaaacttgag atcaagcgca cagttgctgc ccccagcgtg 361 ttcattttcc cacctagcga tgagcagctg aaaagcggta ctgcctctgt cgtatgcttg 421 ctcaacaact tttacccacg tgaggctaag gtgcagtgga aagtggataa tgcacttcaa 481 tctggaaaca gtcaagagtc cgtgacagaa caggacagca aagactcaac ttattcactc 541 tcttccaccc tgactctgtc caaggcagac tatgaaaaac acaaggtata cgcctgcgag 601 gttacacacc agggtttgtc tagtcctgtc accaagtcct tcaatagggg cgaatgt

Protein Sequence Defining the Full Length Ch4F11 Chimeric Light Chain (Mouse Kappa Chain Variable Region and Human Kappa Constant Region) (SEQ ID NO:86)

1 dvvmtqtpls lpvslgdqas iscrssqslv htngntylhw ylqkpgqspk lliykvsnrf 61 sgvpdrfsgs gsgtdftlki srveaedlgv yfcsqsthvp wtfgggtkle ikrtvaapsv 121 fifppsdeql ksgtasvvcl lnnfypreak vqwkvdnalq sgnsqesvte qdskdstysl 181 sstltlskad yekhkvyace vthqglsspv tksfnrgec

Nucleic Acid Sequence Encoding the Full Length Hu4F11 Kv2D-29 Light Chain (Humanized Kappa Chain Variable Region and Human Kappa Constant Region (Version 1)) (SEQ ID NO:87)

1 gatgtagtca tgacccaaac gccgctttcg ttgtcggtga cgcccggaca gcccgcgtca 61 atctcgtgtc ggtcatcgca gtcgttggta cacacaaacg gtaatacgta tctccattgg 121 tatctccaga agcccggcca gtcgccgcag ctcttgatct acaaagtgag caatcgcttt 181 tcgggggtgc cggatcggtt ctcgggatcg gggtcaggaa cggacttcac gcttaagatt 241 tcgagggtcg aggcggagga tgtcggagtc tacttttgtt cgcagtccac acatgtcccc 301 tggacgtttg ggcaggggac gaaggtggaa atcaagcgca cagttgctgc ccccagcgtg 361 ttcattttcc cacctagcga tgagcagctg aaaagcggta ctgcctctgt cgtatgcttg 421 ctcaacaact tttacccacg tgaggctaag gtgcagtgga aagtggataa tgcacttcaa 481 tctggaaaca gtcaagagtc cgtgacagaa caggacagca aagactcaac ttattcactc 541 tcttccaccc tgactctgtc caaggcagac tatgaaaaac acaaggtata cgcctgcgag 601 gttacacacc agggtttgtc tagtcctgtc accaagtcct tcaatagggg cgaatgt

Protein Sequence Defining the Full Length Hu4F11 Kv2D-29 Light Chain (Humanized Kappa Chain Variable Region and Human Kappa Constant Region) (SEQ ID NO:88)

1 dvvmtqtpls lsvtpgqpas iscrssqslv htngntylhw ylqkpgqspq lliykvsnrf 61 sgvpdrfsgs gsgtdftlki srveaedvgv yfcsqsthvp wtfgqgtkve ikrtvaapsv 121 fifppsdeql ksgtasvvcl lnnfypreak vqwkvdnalq sgnsqesvte qdskdstysl 181 sstltlskad yekhkvyace vthqglsspv tksfnrgec

Nucleic Acid Sequence Encoding the Full Length Hu4F11 Kv2D-29 N28H Light Chain (Humanized Kappa Chain Variable Region and Human Kappa Constant Region (Version 2)) (SEQ ID NO:89)

1 gatgtagtca tgacccaaac gccgctttcg ttgtcggtga cgcccggaca gcccgcgtca 61 atctcgtgtc ggtcatcgca gtcgttggta cacacacacg gtaatacgta tctccattgg 121 tatctccaga agcccggcca gtcgccgcag ctcttgatct acaaagtgag caatcgcttt 181 tcgggggtgc cggatcggtt ctcgggatcg gggtcaggaa cggacttcac gcttaagatt 241 tcgagggtcg aggcggagga tgtcggagtc tacttttgtt cgcagtccac acatgtcccc 301 tggacgtttg ggcaggggac gaaggtggaa atcaagcgca cagttgcagc ccccagcgtg 361 ttcattttcc cacctagcga tgagcagctg aaaagcggta ctgcctctgt cgtatgcttg 421 ctcaacaact tttacccacg tgaggctaag gtgcagtgga aagtggataa tgcacttcaa 481 tctggaaaca gtcaagagtc cgtgacagaa caggacagca aagactcaac ttattcactc 541 tcttccaccc tgactctgtc caaggcagac tatgaaaaac acaaggtata cgcctgcgag 601 gttacacacc agggtttgtc tagtcctgtc accaagtcct tcaatagggg cgaatgt

Protein Sequence Defining the Full Length Hu4F11 Kv2D-29 N28H Light Chain (Humanized Kappa Chain Variable Region and Human Kappa Constant Region) (SEQ ID NO:90)

1 dvvmtqtpls lsvtpgqpas iscrssqslv hthgntylhw ylqkpgqspq lliykvsnrf 61 sgvpdrfsgs gsgtdftlki srveaedvgv yfcsqsthvp wtfgqgtkve ikrtvaapsv 121 fifppsdeql ksgtasvvcl lnnfypreak vqwkvdnalq sgnsqesvte qdskdstysl 181 sstltlskad yekhkvyace vthqglsspv tksfnrgec

Nucleic Acid Sequence Encoding the Full Length Hu4F11 Kv2D-29 N28Q Light Chain (Humanized Kappa Chain Variable Region and Human Kappa Constant Region (Version 2)) (SEQ ID NO:91)

1 gatgtagtca tgacccaaac gccgctttcg ttgtcggtga cgcccggaca gcccgcgtca 61 atctcgtgtc ggtcatcgca gtcgttggta cacacacaag gtaatacgta tctccattgg 121 tatctccaga agcccggcca gtcgccgcag ctcttgatct acaaagtgag caatcgcttt 181 tcgggggtgc cggatcggtt ctcgggatcg gggtcaggaa cggacttcac gcttaagatt 241 tcgagggtcg aggcggagga tgtcggagtc tacttttgtt cgcagtccac acatgtcccc 301 tggacgtttg ggcaggggac gaaggtggaa atcaagcgca cagttgcagc ccccagcgtg 361 ttcattttcc cacctagcga tgagcagctg aaaagcggta ctgcctctgt cgtatgcttg 421 ctcaacaact tttacccacg tgaggctaag gtgcagtgga aagtggataa tgcacttcaa 481 tctggaaaca gtcaagagtc cgtgacagaa caggacagca aagactcaac ttattcactc 541 tcttccaccc tgactctgtc caaggcagac tatgaaaaac acaaggtata cgcctgcgag 601 gttacacacc agggtttgtc tagtcctgtc accaagtcct tcaatagggg cgaatgt

Protein Sequence Defining the Full Length Hu4F11 Kv2D-29 N28Q Light Chain (Humanized Kappa Chain Variable Region and Human Kappa Constant Region) (SEQ ID NO:92)

1 dvvmtqtpls lsvtpgqpas iscrssqslv htqgntylhw ylqkpgqspq lliykvsnrf 61 sgvpdrfsgs gsgtdftlki srveaedvgv yfcsqsthvp wtfgqgtkve ikrtvaapsv 121 fifppsdeql ksgtasvvcl lnnfypreak vqwkvdnalq sgnsqesvte qdskdstysl 181 sstltlskad yekhkvyace vthqglsspv tksfnrgec

Nucleic Acid Sequence Encoding the Full Length Hu4F11 Kv2D-29 N28Y Light Chain (Humanized Kappa Chain Variable Region and Human Kappa Constant Region (Version 2)) (SEQ ID NO:93)

1 gatgtagtca tgacccaaac gccgctttcg ttgtcggtga cgcccggaca gcccgcgtca 61 atctcgtgtc ggtcatcgca gtcgttggta cacacatacg gtaatacgta tctccattgg 121 tatctccaga agcccggcca gtcgccgcag ctcttgatct acaaagtgag caatcgcttt 181 tcgggggtgc cggatcggtt ctcgggatcg gggtcaggaa cggacttcac gcttaagatt 241 tcgagggtcg aggcggagga tgtcggagtc tacttttgtt cgcagtccac acatgtcccc 301 tggacgtttg ggcaggggac gaaggtggaa atcaagcgca cagttgcagc ccccagcgtg 361 ttcattttcc cacctagcga tgagcagctg aaaagcggta ctgcctctgt cgtatgcttg 421 ctcaacaact tttacccacg tgaggctaag gtgcagtgga aagtggataa tgcacttcaa 481 tctggaaaca gtcaagagtc cgtgacagaa caggacagca aagactcaac ttattcactc 541 tcttccaccc tgactctgtc caaggcagac tatgaaaaac acaaggtata cgcctgcgag 601 gttacacacc agggtttgtc tagtcctgtc accaagtcct tcaatagggg cgaatgt

Protein Sequence Defining the Full Length Hu4F11 Kv2D-29 N28Y Light Chain (Humanized Kappa Chain Variable Region and Human Kappa Constant Region) (SEQ ID NO:94)

1 dvvmtqtpls lsvtpgqpas iscrssqslv htygntylhw ylqkpgqspq lliykvsnrf 61 sgvpdrfsgs gsgtdftlki srveaedvgv yfcsqsthvp wtfgqgtkve ikrtvaapsv 121 fifppsdeql ksgtasvvcl lnnfypreak vqwkvdnalq sgnsqesvte qdskdstysl 181 sstltlskad yekhkvyace vthqglsspv tksfnrgec

Table 12 is a concordance chart showing the SEQ ID NO. of each sequence discussed in this Example.

TABLE 12 SEQ ID NO. Nucleic Acid or Protein 68 Human IgG1 constant-nucleic acid 69 Human IgG1 constant-protein 70 Human Kappa constant-nucleic acid (version 1) 71 Human Kappa constant-nucleic acid (version 2) 72 Human Kappa constant-protein (nucleic acid versions 1 and 2 encode the same amino acid sequence) 73 Chimeric Ch4F11 Heavy Variable + Human IgG1 constant-nucleic acid 74 Chimeric Ch4F11 Heavy Variable + Human IgG1 constant-protein 75 Humanized Sh4F11 Hv3-23 Heavy Human Variable + Human IgG1 constant-nucleic acid 76 Humanized Sh4F11 Hv3-23 Heavy Human Variable + Human IgG1 constant-protein 77 Humanized Sh4F11 Hv3-23 A28T S31H T62S Heavy Human Variable + Human IgG1 constant-nucleic acid 78 Humanized Sh4F11 Hv3-23 A28T S31H T62S Heavy Human Variable + Human IgG1 constant-protein 79 Humanized Sh4F11 Hv3-23 S31H T62S Heavy Human Variable + Human IgG1 constant-nucleic acid 80 Humanized Sh4F11 Hv3-23 S31H T62S Heavy Human Variable + Human IgG1 constant-protein 81 Humanized Sh4F11 Hv3-23 A28T S31N T62S Heavy Human Variable + Human IgG1 constant-nucleic acid 82 Humanized Sh4F11 Hv3-23 A28T S31N T62S Heavy Human Variable + Human IgG1 constant-protein 83 Humanized Sh4F11 Hv3-23 A28T T62S Heavy Human Variable + Human IgG1 constant-nucleic acid 84 Humanized Sh4F11 Hv3-23 A28T T62S Heavy Human Variable + Human IgG1 constant-protein 85 Chimeric Ch4F11 Kappa Variable + Human Kappa constant- nucleic acid (version 1) 86 Chimeric Ch4F11 Kappa Variable + Human Kappa constant- protein 87 Humanized Hu4F11 Kv2D-29 Kappa Human Variable + Human Kappa constant-nucleic acid (version 1) 88 Humanized Hu4F11 Kv2D-29 Kappa Human Variable + Human Kappa constant-protein 89 Humanized Hu4F11 Kv2D-29 N28H Kappa Human Variable + Human Kappa constant-nucleic acid (version 2) 90 Humanized Hu4F11 Kv2D-29 N28H Kappa Human Variable + Human Kappa constant-protein 91 Humanized Hu4F11 Kv2D-29 N28Q Kappa Human Variable + Human Kappa constant-nucleic acid (version 2) 92 Humanized Hu4F11 Kv2D-29 N28Q Kappa Human Variable + Human Kappa constant-protein 93 Humanized Hu4F11 Kv2D-29 N28Y Kappa Human Variable + Human Kappa constant-nucleic acid (version 2) 94 Humanized Hu4F11 Kv2D-29 N28Y Kappa Human Variable + Human Kappa constant-protein

Table 13 below shows antibodies containing chimeric immunoglobulin heavy and light chains and exemplary combinations of the full-length chimeric or humanized immunoglobulin heavy and light chains.

TABLE 13 Antibody Name Heavy Chain Light Chain Hu4F11-1 Ch4F11 Chimeric Ch4F11 Chimeric Kappa Heavy Variable + Variable + Human Human IgG1 constant Kappa constant (SEQ ID NO: 74) (SEQ ID NO: 86) Hu4F11-10 Humanized Sh4F11 Hv3-23 Ch4F11 Chimeric Kappa Heavy Human Variable + Variable + Human Human IgG1 constant Kappa constant (SEQ ID NO: 76) (SEQ ID NO: 86) Hu4F11-18 Ch4F11 Chimeric Humanized Hu4F11 Kv2D-29 Heavy Variable + Human Variable + Human Human IgG1 constant Kappa constant (SEQ ID NO: 74) (SEQ ID NO: 88) Hu4F11-32 Humanized Sh4F11 Hv3-23 Humanized Hu4F11 Kv2D-29 Heavy Human Variable + Human Kappa Variable + Human IgG1 constant Human Kappa constant (SEQ ID NO: 76) (SEQ ID NO: 88) Hu4F11-69 Humanized Sh4F11 Hv3-23 Humanized Hu4F11 Kv2D-29 A28T S31N T62S N28H Human Kappa Heavy Human Variable + Variable + Human Human IgG1 constant Kappa constant (SEQ ID NO: 82) (SEQ ID NO: 90) Hu4F11-70 Humanized Sh4F11 Hv3-23 Humanized Hu4F11 Kv2D-29 A28T S31H T62S N28H Human Kappa Heavy Human Variable + Variable + Human Human IgG1 constant Kappa constant (SEQ ID NO: 78) (SEQ ID NO: 90) Hu4F11-71 Humanized Sh4F11 Hv3-23 Humanized Hu4F11 Kv2D-29 A28T T62S N28H Human Kappa Heavy Human Variable + Variable + Human Human IgG1 constant Kappa constant (SEQ ID NO: 84) (SEQ ID NO: 90) Hu4F11-72 Humanized Sh4F11 Hv3-23 Humanized Hu4F11 Kv2D-29 S31H T62S N28H Human Kappa Heavy Human Variable + Variable + Human Human IgG1 constant Kappa constant (SEQ ID NO: 80) (SEQ ID NO: 90) Hu4F11-73 Humanized Sh4F11 Hv3-23 Humanized Hu4F11 Kv2D-29 A28T S31N T62S N28Y Human Kappa Heavy Human Variable + Variable + Human Human IgG1 constant Kappa constant (SEQ ID NO: 82) (SEQ ID NO: 94) Hu4F11-74 Humanized Sh4F11 Hv3-23 Humanized Hu4F11 Kv2D-29 A28T S31H T62S N28Y Human Kappa Heavy Human Variable + Variable + Human Human IgG1 constant Kappa constant (SEQ ID NO: 78) (SEQ ID NO: 94) Hu4F11-75 Humanized Sh4F11 Hv3-23 Humanized Hu4F11 Kv2D-29 A28T T62S N28Y Human Kappa Heavy Human Variable + Variable + Human Human IgG1 constant Kappa constant (SEQ ID NO: 84) (SEQ ID NO: 94) Hu4F11-76 Humanized Sh4F11 Hv3-23 Humanized Hu4F11 Kv2D-29 S31H T62S N28Y Human Kappa Heavy Human Variable + Variable + Human Human IgG1 constant Kappa constant (SEQ ID NO: 80) (SEQ ID NO: 94) Hu4F11-77 Humanized Sh4F11 Hv3-23 Humanized Hu4F11 Kv2D-29 A28T S31N T62S N28Q Human Kappa Heavy Human Variable + Variable + Human Human IgG1 constant Kappa constant (SEQ ID NO: 82) (SEQ ID NO: 92) Hu4F11-78 Humanized Sh4F11 Hv3-23 Humanized Hu4F11 Kv2D-29 A28T S31H T62S N28Q Human Kappa Heavy Human Variable + Variable + Human Human IgG1 constant Kappa constant (SEQ ID NO: 78) (SEQ ID NO: 92) Hu4F11-79 Humanized Sh4F11 Hv3-23 Humanized Hu4F11 Kv2D-29 A28T T62S N28Q Human Kappa Heavy Human Variable + Variable + Human Human IgG1 constant Kappa constant (SEQ ID NO: 84) (SEQ ID NO: 92) Hu4F11-80 Humanized Sh4F11 Hv3-23 Humanized Hu4F11 Kv2D-29 S31H T62S N28Q Human Kappa Heavy Human Variable + Variable + Human Human IgG1 constant Kappa constant (SEQ ID NO: 80) (SEQ ID NO: 92)

The antibody construct containing the full length chimeric heavy and light chains is designated below:

-   -   Chimeric 4F11 (Hu4F11-1)=Full Length Ch4F11 Chimeric Heavy Chain         (Mouse Heavy Chain Variable Region and Human IgG1 Constant         Region) (SEQ ID NO:74) plus Full Length Ch4F11 Chimeric Light         Chain (Mouse Kappa Chain Variable Region and Human Kappa         Constant Region) (SEQ ID NO:86)

Thirteen of the possible antibody constructs containing the full length immunoglobulin heavy and light chains containing humanized variable regions are designated below:

-   -   Hu4F11-32=Full Length Sh4F11 Hv3-23 Heavy Chain (Humanized Heavy         Chain Variable Region and Human IgG1 Constant Region) (SEQ ID         NO:76) plus Full Length Hu4F11 Kv2D-29 Light Chain (Humanized         Kappa Chain Variable Region and Human Kappa Constant Region)         (SEQ ID NO:88)     -   Hu4F11-69=Full Length Sh4F11 Hv3-23 A28T S31N T62S_Heavy Chain         (Humanized Heavy Chain Variable Region and Human IgG1 Constant         Region) (SEQ ID NO:82) plus Full Length Hu4F11 Kv2D-29 N28H         Light Chain (Humanized Kappa Chain Variable Region and Human         Kappa Constant Region) (SEQ ID NO:90)     -   Hu4F11-70=Full Length Sh4F11 Hv3-23 A28T S31H T62S Heavy Chain         (Humanized Heavy Chain Variable Region and Human IgG1 Constant         Region) (SEQ ID NO:78) plus Full Length Hu4F11 Kv2D-29 N28H         Light Chain (Humanized Kappa Chain Variable Region and Human         Kappa Constant Region) (SEQ ID NO:90)     -   Hu4F11-71=Full Length Sh4F11 Hv3-23 A28T T62S Heavy Chain         (Humanized Heavy Chain Variable Region and Human IgG1 Constant         Region) (SEQ ID NO:84) plus Full Length Hu4F11 Kv2D-29 N28H         Light Chain (Humanized Kappa Chain Variable Region and Human         Kappa Constant Region) (SEQ ID NO:90)     -   Hu4F11-72=Full Length Sh4F11 Hv3-23 S31H T62S Heavy Chain         (Humanized Heavy Chain Variable Region and Human IgG1 Constant         Region) (SEQ ID NO:80) plus Full Length Hu4F11 Kv2D-29 N28H         Light Chain (Humanized Kappa Chain Variable Region and Human         Kappa Constant Region) (SEQ ID NO:90)     -   Hu4F11-73=Full Length Sh4F11 Hv3-23 A28T S31N T62S_Heavy Chain         (Humanized Heavy Chain Variable Region and Human IgG1 Constant         Region) (SEQ ID NO:82) plus Full Length Hu4F11 Kv2D-29 N28Y         Light Chain (Humanized Kappa Chain Variable Region and Human         Kappa Constant Region) (SEQ ID NO:94)     -   Hu4F11-74=Full Length Sh4F11 Hv3-23 A28T S31H T62S Heavy Chain         (Humanized Heavy Chain Variable Region and Human IgG1 Constant         Region) (SEQ ID NO:78) plus Full Length Hu4F11 Kv2D-29 N28Y         Light Chain (Humanized Kappa Chain Variable Region and Human         Kappa Constant Region) (SEQ ID NO:94)     -   Hu4F11-75=Full Length Sh4F11 Hv3-23 A28T T62S Heavy Chain         (Humanized Heavy Chain Variable Region and Human IgG1 Constant         Region) (SEQ ID NO:84) plus Full Length Hu4F11 Kv2D-29 N28Y         Light Chain (Humanized Kappa Chain Variable Region and Human         Kappa Constant Region) (SEQ ID NO:94)     -   Hu4F11-76=Full Length Sh4F11 Hv3-23 S31H T62S Heavy Chain         (Humanized Heavy Chain Variable Region and Human IgG1 Constant         Region) (SEQ ID NO:80) plus Full Length Hu4F11 Kv2D-29 N28Y         Light Chain (Humanized Kappa Chain Variable Region and Human         Kappa Constant Region) (SEQ ID NO:94)     -   Hu4F11-77=Full Length Sh4F11 Hv3-23 A28T S31N T62S_Heavy Chain         (Humanized Heavy Chain Variable Region and Human IgG1 Constant         Region) (SEQ ID NO:82) plus Full Length Hu4F11 Kv2D-29 N28Q         Light Chain (Humanized Kappa Chain Variable Region and Human         Kappa Constant Region) (SEQ ID NO:92)     -   Hu4F11-78=Full Length Sh4F11 Hv3-23 A28T S31H T62S Heavy Chain         (Humanized Heavy Chain Variable Region and Human IgG1 Constant         Region) (SEQ ID NO:78) plus Full Length Hu4F11 Kv2D-29 N28Q         Light Chain (Humanized Kappa Chain Variable Region and Human         Kappa Constant Region) (SEQ ID NO:92)     -   Hu4F11-79=Full Length Sh4F11 Hv3-23 A28T T62S Heavy Chain         (Humanized Heavy Chain Variable Region and Human IgG1 Constant         Region) (SEQ ID NO:84) plus Full Length Hu4F11 Kv2D-29 N28Q         Light Chain (Humanized Kappa Chain Variable Region and Human         Kappa Constant Region) (SEQ ID NO:92)     -   Hu4F11-80=Full Length Sh4F11 Hv3-23 S31H T62S Heavy Chain         (Humanized Heavy Chain Variable Region and Human IgG1 Constant         Region) (SEQ ID NO:80) plus Full Length Hu4F11 Kv2D-29 N28Q         Light Chain (Humanized Kappa Chain Variable Region and Human         Kappa Constant Region) (SEQ ID NO:92)

Example 9 Binding Affinities of Humanized and Chimeric Anti-Notch3 Monoclonal Antibodies

The binding affinities and kinetics of binding of chimeric and humanized antibodies to monomeric recombinant human Notch3 extracellular domain (containing EGF like domains 1-11) fusion protein (monomeric rhNotch3) and monomeric recombinant cynomologus monkey Notch3 extracellular domain (containing EGF like domains 1-12) fusion protein (monomeric rcNotch3) were measured by surface plasmon resonance, using a BIAcore® T100 instrument (GE Healthcare, Piscataway, N.J.).

Goat anti-human IgGs (Fc fragment specific, Jackson ImmunoResearch, West Grove, Pa.) were immobilized on carboxymethylated dextran CM4 sensor chips by amine coupling, according to a standard protocol. Analyses were performed at 25 and 37° C. using PBS containing 0.05% surfactant P20 as running buffer. The antibodies were captured in individual flow cells at a flow rate of 10 μL/minute. Injection time was varied for each antibody to yield an Rmax between 30 and 60 RU. Buffer or Notch3 protein diluted in running buffer was injected sequentially over a reference surface (no antibody captured) and the active surface (antibody to be tested) for 240 seconds at 60 μL/minute. The dissociation phase was monitored for up to 900 seconds. The surface was then regenerated with two 60-second injections of 10 mM Glycine-HCl, pH 2.25, at a flow rate of 30 μL/minute. The Notch3 concentration range tested was 50 nM to 6.25 nM.

Kinetic parameters were determined using the kinetic function of the BIAevaluation software (GE Healthcare) with double reference subtraction. Kinetic parameters for each antibody, k_(a) (association rate constant), k_(d) (dissociation rate constant), and K_(D) (equilibrium dissociation constant) were determined Kinetic values of purified monoclonal antibodies on monomeric rcNotch3 at 25° C. are summarized in Table 14.

TABLE 14 Antibody k_(a) (1/Ms) k_(d) (1/s) K_(D) (M) n Hu4F11-1 4.8E+05 1.0E−02 2.4E−08 5 Hu4F11-32 7.9E+05 7.5E−03 1.8E−08 8 Hu4F11-69 1.2E+05 9.4E−04 7.7E−09 1 Hu4F11-70 2.0E+05 1.0E−03 5.2E−09 1 Hu4F11-71 1.5E+06 4.0E−03 2.7E−09 1 Hu4F11-72 2.8E+06 4.5E−03 1.6E−09 1 Hu4F11-73 7.6E+05 1.9E−03 2.6E−09 1 Hu4F11-74 9.0E+05 2.5E−03 2.8E−09 1 Hu4F11-75 7.2E+05 2.6E−03 3.7E−09 1 Hu4F11-76 7.8E+05 1.9E−03 2.5E−09 1 Hu4F11-77 9.6E+05 2.5E−03 2.6E−09 1 Hu4F11-78 1.8E+06 3.8E−03 2.2E−09 1 Hu4F11-79 1.3E+06 4.6E−03 3.4E−09 1 Hu4F11-80 8.2E+05 3.2E−03 4.0E−09 1

Additional kinetic measurements were conducted for each antibody shown in Table 14. These measurements confirmed that the antibodies have affinities ranging from about 1 nM to about 25 nM for monomeric rcNotch3 at 25° C.

Kinetic values of purified monoclonal antibodies on monomeric rcNotch3 at 37° C. are summarized in Table 15.

TABLE 15 Antibody k_(a) (1/Ms) k_(d) (1/s) K_(D) (M) n Hu4F11-32 5.0E+05 1.6E−02 3.2E−08 5 Hu4F11-69 4.0E+05 3.8E−03 1.1E−08 3 Hu4F11-70 3.7E+05 2.9E−03 9.1E−09 3 Hu4F11-71 4.1E+05 5.6E−03 1.4E−08 3 Hu4F11-72 4.4E+05 3.2E−03 9.8E−09 3 Hu4F11-73 5.0E+05 6.3E−03 1.5E−08 3 Hu4F11-74 4.4E+05 4.5E−03 1.2E−08 3 Hu4F11-75 3.8E+05 8.9E−03 2.4E−08 3 Hu4F11-76 5.4E+05 6.2E−03 1.2E−08 3 Hu4F11-77 9.1E+05 1.0E−02 1.2E−08 3 Hu4F11-78 6.6E+05 7.0E−03 1.1E−08 3 Hu4F11-79 9.8E+05 2.1E−02 2.3E−08 3 Hu4F11-80 9.1E+05 1.0E−02 1.2E−08 3

Additional kinetic measurements were conducted for each antibody shown in Table 15. These measurements confirmed that the antibodies have affinities ranging from about 9 nM to about 35 nM for monomeric rcNotch3 at 37° C.

Kinetic values of purified monoclonal antibodies on monomeric rhNotch3 at 37° C. are summarized in Table 16.

TABLE 16 Antibody k_(a) (1/Ms) k_(d) (1/s) K_(D) (M) n Hu4F11-32 1.7E+06 4.6E−03 2.7E−09 1 Hu4F11-69 1.3E+06 3.8E−03 2.9E−09 1 Hu4F11-70 9.4E+05 2.8E−03 3.0E−09 1 Hu4F11-71 1.2E+06 3.7E−03 3.0E−09 1 Hu4F11-72 1.8E+05 9.4E−04 5.2E−09 1 Hu4F11-73 2.1E+05 1.3E−03 5.9E−09 1 Hu4F11-74 5.6E+05 2.2E−03 3.9E−09 1 Hu4F11-75 2.7E+06 9.0E−03 3.4E−09 1 Hu4F11-76 1.7E+06 5.5E−03 3.3E−09 1 Hu4F11-77 2.2E+06 7.3E−03 3.3E−09 1 Hu4F11-78 1.5E+06 5.5E−03 3.8E−09 1 Hu4F11-79 1.8E+06 6.0E−03 3.2E−09 1 Hu4F11-80 1.1E+06 4.1E−03 3.8E−09 1

Additional kinetic measurements were conducted for each antibody shown in Table 16. The additional measurements were averaged together with those presented in Table 16. These combined measurements indicated that the antibodies have affinities ranging from about 7 nM to about 16 nM for monomeric rhNotch3 at 37° C. (Table 17).

TABLE 17 Antibody k_(a) (1/Ms) k_(d) (1/s) K_(D) (M) n Hu4F11-32 7.4E+06 8.4E−02 7.6E−09 2 Hu4F11-69 7.1E+05 3.7E−03 8.5E−09 3 Hu4F11-70 6.9E+05 3.9E−03 7.5E−09 4 Hu4F11-71 1.1E+06 9.5E−03 9.2E−09 3 Hu4F11-72 7.1E+05 6.9E−03 7.0E−09 4 Hu4F11-73 4.9E+05 4.6E−03 1.1E−08 3 Hu4F11-74 4.9E+05 5.1E−03 1.0E−08 4 Hu4F11-75 1.7E+06 1.3E−02 1.0E−08 3 Hu4F11-76 9.8E+05 6.4E−03 8.2E−09 3 Hu4F11-77 1.2E+06 7.4E−03 8.6E−09 3 Hu4F11-78 8.2E+05 6.0E−03 9.0E−09 4 Hu4F11-79 9.0E+05 9.1E−03 1.6E−08 3 Hu4F11-80 5.9E+05 5.6E−03 1.4E−08 3

The results in Tables 14-17 demonstrate that the chimeric and each of the humanized antibodies, have fast association rates (k_(a)), very slow disassociation rates (k_(d)) and very high affinities (K_(D)). In particular, the antibodies have affinities ranging from about 1 nM to about 35 nM.

Example 10 Binding of Humanized 4F11 Antibodies to Cell Surface-Expressed Notch3

Binding of humanized 4F11 variants to cell surface Notch3 receptor was confirmed by FACS. FlpIn™ CHO lines stably expressing human Notch3, or FlpIn™ CHO lines expressing no human Notch receptors, were used for binding experiments. CHO cells were harvested using Cell Dissociation Buffer (Life Technologies, Grand Island, N.Y.) and resuspended at 2.5×10⁶ cells/ml in PBS/0.5% BSA. 100 μl of cell suspension per sample was added to a 96 well v-bottom plate. 4F11 humanized antibodies or human IgG were added at 5 ng/ml to the wells, mixed, and incubated on ice for one hour. After washing with PBS/0.5% BSA, anti-human PE conjugated secondary antibody was added at a 1:100 dilution in PBS/0.5% BSA and allowed to incubate on ice in the dark for 30 minutes. Cells were washed with PBS/0.5% BSA, then resuspended in 300 μl PBS/0.5% BSA and FACS analysis was performed. Expression of human Notch3 receptor was confirmed using anti-human Notch3 PE (BioLegend, San Diego, Calif.) as a positive control. FACS analysis confirmed that the humanized 4F11 antibody variants bind to human Notch3 expressed on the cell surface.

Example 11 Inhibition of Ligand-Induced Notch3 ICD Cleavage by Humanized 4F11 Antibodies

Selected humanized 4F11 variants were tested for their ability to inhibit ligand-induced activation of Notch3, as measured by the presence of cleaved ICD. The MDA-MB-468 breast cancer cell line, which expresses endogenous human Notch3, was plated in 96-well plates previously coated with hJag2-mFc fusion protein. The wells were prepared by diluting a-mouse Fc (Jackson ImmunoResearch, West Grove, Pa.) to 5 ng/ml in sterile-filtered carbonate-bicarbonate coating buffer, pH 9.4 (Thermo Fisher Scientific, Rockland, Md.). Then 100 μl of the diluted antibody was added to each well of a 96-well Maxisorp™ plate and incubated overnight at 4° C. The next day, wells were washed three times with PBS/0.5% BSA before adding 100 μl of soluble Jag2-mFc fusion protein or mouse IgG Fc (Jackson Immunolabs) diluted to 5 μg/ml in PBS/0.5% BSA. After incubating for two hours at room temperature on an orbital shaker, the wells were washed three times with PBS/0.5% BSA to remove unbound ligand. MDA-MB-468 cells were counted and resuspended in fresh growth media at 0.4×10⁶ cells/ml. Cells were pre-incubated with 10 ng/ml of the 4F11 humanized antibodies for 30 minutes at 37° C., before seeding 100 μl of the suspension into 96-well plates coated with hJag2-mFc ligand or mFc. Cells were incubated overnight at 37° C. The next day wells were gently washed with ice cold PBS, then cells harvested by adding RIPA buffer containing protease inhibitors directly to the well. Lysates were clarified by centrifugation in a refrigerated microcentrifuge. Supernatants were boiled with 5× SDS sample buffer before loading onto an SDS PAGE gel and Western blotting. Blots were probed with a α-Notch3 antibody to detect the cleaved intracellular domain (Cell Signaling, Danvers, Mass.). The same blots were also probed with anti-β tubulin (Cell Signaling) for use as a loading control. Bands were quantitated using ImageLab software (BioRad, Hercules, Calif.) and values adjusted relative to their respective loading control. Each sample was then normalized relative to the value of the Notch3 ICD band from cells plated on wells without ligand in the presence of hIgG control antibody.

The humanized 4F11 antibody variants significantly inhibit ligand-induced cleavage of the Notch3 ICD as summarized in FIG. 11.

Example 12 Inhibition of Notch3-Dependent Transcription by Humanized 4F11 Antibodies

Luciferase reporter assays were used to assess the ability of certain humanized 4F11 antibodies to inhibit ligand-dependent Notch3 receptor signaling and transcriptional activity. HCC1143 reporter lines co-cultured with CHO cells expressing Notch ligands were utilized for these assays.

Stable lines expressing full length Notch ligands at the cell surface were produced by transfecting FlpIn™ CHO cells with Jag1, Jag2, DLL1, or DLL4 cDNAs cloned into the pcDNASFRT vector using Lipofectamine 2000 (Life Technologies) according to the manufacturer's protocol. Twenty-four hours after transfection, CHO cells were split into F12 media containing 10% FBS, 2 mM L-Glutamine and 700 μg/ml hygromycin B (Sigma-Aldrich, St. Louis, Mo.) to select for transfected cells. Expression of Notch ligands was confirmed by FACS analysis using antibodies against Jag 1 (R&D Systems, Inc., Minneapolis, Minn.), Jag2 (R&D Systems), DLL1 (R&D Systems), and DLL4 (BioLegend, San Diego, Calif.).

FlpIn™ CHO lines stably expressing Notch ligands were trypsinized, counted and seeded in 96-well plates at 60K cells/well in 100 μl of Ham's F12 K media without hygromycin B. The next day, HCC1143 reporter cells were spun down and resuspended in RPMI media containing 2% FBS at 0.2×10⁶ cells/ml. Antibodies were serially diluted into RPMI without FBS, and 100 μl of antibody solution was added to an equal volume of reporter cells for 30 minutes at 37° C. in a 5% CO2 incubator. After removing media from the hJag2 CHO cells, 100 μl of the HCC1143 reporter/antibody mix was added to the ligand-expressing cells and allowed to incubate at 37° C. overnight. Twenty-four hours later, 96-well plates placed at room temperature for 20 minutes, then processed with the Bright Glo (Promega, Madison, Wis.) reporter assay protocol per the manufacturer's instructions. Lysates were transferred to white-walled 96 well plates (Greiner Bio-One, Frickenhausen, Germany) and read on a GloMax Luminometer (Promega) using the Bright Glo program.

As shown in FIG. 12A-B, the humanized 4F11 antibody variants inhibit activation of ligand-induced transcription in the HCC1143 reporter cell line.

Example 13 Inhibition of Notch3 ICD Cleavage in vivo

Selected humanized 4F11 antibodies (i.e., Hu4F11-70, Hu4F11-72, Hu4F11-78) were tested for their ability to inhibit cleavage of Notch3 ICD expressed in HCC2429 tumors in vivo.

All mice were treated in accordance with the OLAW Public Health Service Policy on Human Care and Use of Laboratory Animals and the ILAR Guide for the Care and Use of Laboratory Animals. All in vivo studies were conducted following the protocols approved by the AVEO Institutional Animal Care and Use Committee. HCC2429 is a lung cancer cell line harboring a translocation of chromosome 19 that results in overexpression of the Notch3 receptor. For the Notch3 ICD cleavage experiments, approximately thirteen week old NCR nude mice (Taconic, Germantown, N.Y.) were inoculated subcutaneously into the right flank with 5×10⁶ cells in 1:1 DMEM+Matrigel (Invitrogen, Carlsbad, Calif.)/Matrigel (BD Biosciences, San Jose, Calif.). Tumor measurements were taken twice weekly, using vernier calipers. Tumor volume was calculated using the formula: V=0.5×width×width×length. When tumors approached a volume of 300-400 mm³, mice were randomized into groups of three animals each (corresponds to mouse 1 (ml) through mouse 3 (m3), as designated in FIG. 13). The next day, mice were treated with 20 mg/kg hIgG (control), or 20 mg/kg of antibodies Hu4F11-70, Hu4F11-72, Hu4F11-78 or murine 4F11 (mu4F11) by intraperitoneal injection. Mice were dosed once, and tumors were collected 24 hours later and snap frozen.

To assess levels of cleaved Notch3 ICD, tumors were pulverized using a Covaris cryoPREP™ impactor (Covaris, Woburn, Mass.), resuspended in RIPA buffer (Boston BioProducts) containing protease inhibitors, and rotated at 4° C. for 1 hour. Lysates were clarified by spinning at 14 k rpm for 15 minutes in a refrigerated microcentrifuge. Protein concentration for each sample was measured using the BioRad DC protein assay (BioRad). Equal concentrations of protein from each sample were loaded onto an SDS PAGE gel and transferred onto nitrocellulose by Western blotting. Blots were probed with antibody against the C-terminus of Notch3 (Cell Signaling) to detect levels of the cleaved ICD. Blots were also probed with antibody against β-tubulin (Cell Signaling) for use as a loading control. Bands were quantified using Image Lab 3.0 software (BioRad), and the intensity of Notch3 ICD bands were normalized to their respective β-tubulin loading control. All humanized 4F11 antibodies tested (i.e., Hu4F11-70, Hu4F11-72, Hu4F11-78) significantly inhibit Notch3 activation in vivo, as measured by Notch3 ICD levels present in tumors 24 hours after single dose antibody treatment (FIG. 13).

INCORPORATION BY REFERENCE

The entire disclosure of each of the patent documents and scientific articles referred to herein is incorporated by reference for all purposes.

EQUIVALENTS

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof The foregoing embodiments are therefore to be considered in all respects illustrative rather than limiting on the invention described herein. Scope of the invention is thus indicated by the appended claims rather than by the foregoing description, and all changes that come within the meaning and the range of equivalency of the claims are intended to be embraced therein. 

1. An isolated antibody that binds human Notch3 comprising an immunoglobulin heavy chain variable region and an immunoglobulin light chain variable region selected from the group consisting of: (a) (i) an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising the amino acid sequence of SEQ ID NO:51, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO:53, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO:7; and (ii) an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO:62, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO:9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO:10; (b) (i) an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 5 and SEQ ID NO:11; a CDR_(H2) comprising the amino acid sequence of SEQ ID NO: 6; and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO: 7; and (ii) an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO: 8; a CDR_(L2) comprising the amino acid sequence of SEQ ID NO: 9; and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO: 10; (c) (i) an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 5 and SEQ ID NO:11; a CDR_(H2) comprising the amino acid sequence of SEQ ID NO: 6; and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO: 7; and (ii) an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO: 62; a CDR_(L2) comprising the amino acid sequence of SEQ ID NO: 9; and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO: 10; (d) (i) an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 5 and SEQ ID NO:11; a CDR_(H2) comprising the amino acid sequence of SEQ ID NO: 6; and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO: 7; and (ii) an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO: 63; a CDR_(L2) comprising the amino acid sequence of SEQ ID NO: 9; and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO: 10; (e) (i) an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 5 and SEQ ID NO:11; a CDR_(H2) comprising the amino acid sequence of SEQ ID NO: 6; and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO: 7; and (ii) an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO: 64; a CDR_(L2) comprising the amino acid sequence of SEQ ID NO: 9; and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO: 10; (f) (i) an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising the amino acid sequence of SEQ ID NO:51, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO:53, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO:7; and (ii) an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO:8, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO:9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO:10; (g) (i) an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising the amino acid sequence of SEQ ID NO:51, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO:53, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO:7; and (ii) an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO:63, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO:9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO:10; (h) (i) an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising the amino acid sequence of SEQ ID NO:51, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO:53, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO:7; and (ii) an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO:64, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO:9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO:10; (i) (i) an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO:52 and SEQ ID NO: 56, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO:53, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO:7; and (ii) an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO:8, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO:9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO:10; (j) (i) an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO:52 and SEQ ID NO: 56, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO:53, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO:7; and (ii) an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO:62, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO:9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO:10; (k) (i) an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO:52 and SEQ ID NO: 56, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO:53, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO:7; and (ii) an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO:63, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO:9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO:10; (l) (i) an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO:52 and SEQ ID NO: 56, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO:53, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO:7; and (ii) an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO:64, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO:9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO:10; (m) (i) an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO:5 and SEQ ID NO: 57, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO:53, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO:7; and (ii) an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO:8, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO:9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO:10; (n) (i) an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO:5 and SEQ ID NO: 57, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO:53, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO:7; and (ii) an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO:62, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO:9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO:10; (o) (i) an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO:5 and SEQ ID NO: 57, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO:53, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO:7; and (ii) an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO:63, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO:9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO:10; and (p) (i) an immunoglobulin heavy chain variable region comprising a CDR_(H1) comprising an amino acid sequence selected from the group consisting of SEQ ID NO:5 and SEQ ID NO: 57, a CDR_(H2) comprising the amino acid sequence of SEQ ID NO:53, and a CDR_(H3) comprising the amino acid sequence of SEQ ID NO:7; and (ii) an immunoglobulin light chain variable region comprising a CDR_(L1) comprising the amino acid sequence of SEQ ID NO:64, a CDR_(L2) comprising the amino acid sequence of SEQ ID NO:9, and a CDR_(L3) comprising the amino acid sequence of SEQ ID NO:10.
 2. The antibody of claim 1, wherein the CDR sequences are interposed between human or humanized framework sequences.
 3. An isolated nucleic acid comprising a nucleotide sequence encoding an immunoglobulin heavy chain variable region of claim
 1. 4. An isolated nucleic acid comprising a nucleotide sequence encoding an immunoglobulin light chain variable region of claim
 1. 5. An expression vector comprising the nucleic acid of claim
 3. 6. An expression vector comprising the nucleic acid of claim
 4. 7. The expression vector of claim 6, further comprising the nucleic acid of claim
 3. 8. A host cell comprising the expression vector of claim
 5. 9. A host cell comprising the expression vector of claim
 6. 10. A host cell comprising the expression vector of claim
 7. 11. A host cell of claim 9, further comprising the expression vector of claim
 5. 12. A method of producing a polypeptide comprising an immunoglobulin heavy chain variable region or an immunoglobulin light chain variable region, the method comprising: (a) growing the host cell of claim 8 or 9 under conditions so that the host cell expresses the polypeptide comprising the immunoglobulin heavy chain variable region or the immunoglobulin light chain variable region; and (b) purifying the polypeptide comprising the immunoglobulin heavy chain variable region or the immunoglobulin light chain variable region.
 13. A method of producing an antibody that binds human Notch3 or an antigen binding fragment of the antibody, the method comprising: (a) growing the host cell of claim 10 under conditions so that the host cell expresses a polypeptide or polypeptides comprising the immunoglobulin heavy chain variable region and the immunoglobulin light chain variable region, thereby producing the antibody or the antigen-binding fragment of the antibody; and (b) purifying the antibody or the antigen-binding fragment of the antibody.
 14. An isolated antibody that binds human Notch3 comprising an immunoglobulin heavy chain variable region and an immunoglobulin light chain variable region selected from the group consisting of: (a) an immunoglobulin heavy chain variable region comprising the amino acid sequence of SEQ ID NO:36 (Sh4F11 Hv3-23 A28T S31H T62S), and an immunoglobulin light chain variable region comprising the amino acid sequence of SEQ ID NO:46 (Hu4F11 Kv2D-29 N28H); (b) an immunoglobulin heavy chain variable region comprising the amino acid sequence of SEQ ID NO:2 (4F11, Ch4F11 Chimeric), and an immunoglobulin light chain variable region comprising the amino acid sequence of SEQ ID NO:4 (4F11, Ch4F11 Chimeric); (c) an immunoglobulin heavy chain variable region comprising the amino acid sequence of SEQ ID NO:2 (4F11, Ch4F11 Chimeric), and an immunoglobulin light chain variable region comprising the amino acid sequence of SEQ ID NO:44 (Hu4F11 Kv2D-29); (d) an immunoglobulin heavy chain variable region comprising the amino acid sequence of SEQ ID NO:34 (Sh4F11 Hv3-23), and an immunoglobulin light chain variable region comprising the amino acid sequence of SEQ ID NO:4 (4F11, Ch4F11 Chimeric); (e) an immunoglobulin heavy chain variable region comprising the amino acid sequence of SEQ ID NO:34 (Sh4F11 Hv3-23), and an immunoglobulin light chain variable region comprising the amino acid sequence of SEQ ID NO:44 (Hu4F11 Kv2D-29); (f) an immunoglobulin heavy chain variable region comprising the amino acid sequence of SEQ ID NO:38 (Sh4F11 Hv3-23 S31H T62S), and an immunoglobulin light chain variable region comprising the amino acid sequence of SEQ ID NO:46 (Hu4F11 Kv2D-29 N28H); (g) an immunoglobulin heavy chain variable region comprising the amino acid sequence of SEQ ID NO:40 (Sh4F11 Hv3-23 A28T S31N T62S), and an immunoglobulin light chain variable region comprising the amino acid sequence of SEQ ID NO:46 (Hu4F11 Kv2D-29 N28H); (h) an immunoglobulin heavy chain variable region comprising the amino acid sequence of SEQ ID NO:42 (Sh4F11 Hv3-23 A28T T62S), and an immunoglobulin light chain variable region comprising the amino acid sequence of SEQ ID NO:46 (Hu4F11 Kv2D-29 N28H); an immunoglobulin heavy chain variable region comprising the amino acid sequence of SEQ ID NO:36 (Sh4F11 Hv3-23 A28T S31H T62S), and an immunoglobulin light chain variable region comprising the amino acid sequence of SEQ ID NO:48 (Hu4F11 Kv2D-29 N28Q); an immunoglobulin heavy chain variable region comprising the amino acid sequence of SEQ ID NO:38 (Sh4F11 Hv3-23 S31H T62S), and an immunoglobulin light chain variable region comprising the amino acid sequence of SEQ ID NO:48 (Hu4F11 Kv2D-29 N28Q); (k) an immunoglobulin heavy chain variable region comprising the amino acid sequence of SEQ ID NO:40 (Sh4F11 Hv3-23 A28T S31N T62S), and an immunoglobulin light chain variable region comprising the amino acid sequence of SEQ ID NO:48 (Hu4F11 Kv2D-29 N28Q); (l) an immunoglobulin heavy chain variable region comprising the amino acid sequence of SEQ ID NO:42 (Sh4F11 Hv3-23 A28T T62S), and an immunoglobulin light chain variable region comprising the amino acid sequence of SEQ ID NO:48 (Hu4F11 Kv2D-29 N28Q); (m) an immunoglobulin heavy chain variable region comprising the amino acid sequence of SEQ ID NO:36 (Sh4F11 Hv3-23 A28T S31H T62S), and an immunoglobulin light chain variable region comprising the amino acid sequence of SEQ ID NO:50 (Hu4F11 Kv2D-29 N28Y); (n) an immunoglobulin heavy chain variable region comprising the amino acid sequence of SEQ ID NO:38 (Sh4F11 Hv3-23 S31H T62S), and an immunoglobulin light chain variable region comprising the amino acid sequence of SEQ ID NO:50 (Hu4F11 Kv2D-29 N28Y); (o) an immunoglobulin heavy chain variable region comprising the amino acid sequence of SEQ ID NO:40 (Sh4F11 Hv3-23 A28T S31N T62S), and an immunoglobulin light chain variable region comprising the amino acid sequence of SEQ ID NO:50 (Hu4F11 Kv2D-29 N28Y); and (p) an immunoglobulin heavy chain variable region comprising the amino acid sequence of SEQ ID NO:42 (Sh4F11 Hv3-23 A28T T62S), and an immunoglobulin light chain variable region comprising the amino acid sequence of SEQ ID NO:50 (Hu4F11 Kv2D-29 N28Y). 15-25. (canceled)
 26. An isolated antibody that binds human Notch3 comprising an immunoglobulin heavy chain and an immunoglobulin light chain selected from the group consisting of: (a) an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 78 (Sh4F11 Hv3-23 A28T S31H T62S), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 90 (Hu4F11 Kv2D-29 N28H Kappa); (b) an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 27 (4F11), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 29 (4F11); (c) an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 74 (Ch4F11), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 86 (Ch4F11); (d) an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 74 (Ch4F11), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 88 (Hu4F11 Kv2D-29); (e) an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 76 (Sh4F11 Hv3-23), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 86 (Ch4F11); (f) an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 76 (Sh4F11 Hv3-23), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 88 (Hu4F11 Kv2D-29); (g) an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 80 (Sh4F11 Hv3-23 S31H T62S), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 90 (Hu4F11 Kv2D-29 N28H Kappa); (h) an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 82 (Sh4F11 Hv3-23 A28T S31N T62S), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 90 (Hu4F11 Kv2D-29 N28H Kappa); (i) an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 84 (Sh4F11 Hv3-23 A28T T62S), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 90 (Hu4F11 Kv2D-29 N28H Kappa); (j) an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 78 (Sh4F11 Hv3-23 A28T S31H T62S), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 92 (Hu4F11 Kv2D-29 N28Q Kappa); (k) an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 80 (Sh4F11 Hv3-23 S31H T62S), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 92 (Hu4F11 Kv2D-29 N28Q Kappa); (1) an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 82 (Sh4F11 Hv3-23 A28T S31N T62S), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 92 (Hu4F11 Kv2D-29 N28Q Kappa); (m) an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 84 (Sh4F11 Hv3-23 A28T T62S), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 92 (Hu4F11 Kv2D-29 N28Q Kappa); (n) an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 78 (Sh4F11 Hv3-23 A28T S31H T62S), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 94 (Hu4F11 Kv2D-29 N28Y Kappa); (o) an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 80 (Sh4F11 Hv3-23 S31H T62S), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 94 (Hu4F11 Kv2D-29 N28Y Kappa); (p) an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 82 (Sh4F11 Hv3-23 A28T S31N T62S), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 94 (Hu4F11 Kv2D-29 N28Y Kappa); and (q) an immunoglobulin heavy chain comprising the amino acid sequence of SEQ ID NO: 84 (Sh4F11 Hv3-23 A28T T62S), and an immunoglobulin light chain comprising the amino acid sequence of SEQ ID NO: 94 (Hu4F11 Kv2D-29 N28Y Kappa). 27-37. (canceled)
 38. A method of inhibiting or reducing proliferation of a tumor cell comprising exposing the cell to an effective amount of the antibody of claim 1 to inhibit or reduce proliferation of the tumor cell.
 39. A method of inhibiting or reducing tumor growth in a mammal, the method comprising exposing the mammal to an effective amount of the antibody of claim 1, to inhibit or reduce proliferation of the tumor.
 40. (canceled)
 41. A method of treating cancer in a human subject, the method comprising administering to the subject an effective amount of the antibody of claim 1, to a human subject in need thereof.
 42. (canceled)
 43. The antibody of claim 1, wherein the antibody has a K_(D) of 35 nM or lower as measured by surface plasmon resonance. 44-47. (canceled)
 48. An isolated antibody that competes with the antibody of claim 1 for binding to the extracellular domain of human Notch3.
 49. An isolated antibody that competes with the antibody of claim 1 for binding to EGF-like repeats 1-11 of human Notch3.
 50. An isolated antibody that binds to the same epitope on human Notch3 as the antibody of claim
 1. 51. A method of producing an antibody that binds human Notch3 or an antigen binding fragment of the antibody, the method comprising: (a) growing the host cell of claim 11 under conditions so that the host cell expresses a polypeptide or polypeptides comprising the immunoglobulin heavy chain variable region and the immunoglobulin light chain variable region, thereby producing the antibody or the antigen-binding fragment of the antibody; and (b) purifying the antibody or the antigen-binding fragment of the antibody. 